The method of tree-ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution.

1,2851,1871,2221,1941,2681,3161,2751,3171,275

Required:
a. Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviations.
b. Find a 90% confidence interval for the mean of all tree-ring dates from this archaeological site. (Round your answers to the nearest whole number.)

Answers

Answer 1

Answer:

a) The sample mean is 1260 and the standard deviation is 48.

b) The 90% confidence interval for the mean of all tree-ring dates from this archaeological site is (1230, 1290).

Step-by-step explanation:

Question a:

Mean is the sum of all values divided by the number of values. So

[tex]\overline{x} = \frac{1285 + 1187 + 1222 + 1194 + 1268 + 1316 + 1275 + 1317 + 1275}{9} = 1260[/tex]

Standard deviation is the square root of the sum of the differences squared between each value and the mean, divided by the one less than the sample size. So

[tex]s = \sqrt{\frac{(1285-1260)^2 + (1187-1260)^2 + (1222-1260)^2 + (1194-1260)^2 + (1268-1260)^2 + ...}{8}} = 48[/tex]

The sample mean is 1260 and the standard deviation is 48.

Question b:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So

df = 9 - 1 = 8

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 8 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.8595

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.8595\frac{48}{\sqrt{9}} = 30[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 1260 - 30 = 1230

The upper end of the interval is the sample mean added to M. So it is 1260 + 30 = 1290

The 90% confidence interval for the mean of all tree-ring dates from this archaeological site is (1230, 1290).


Related Questions

If using the method of completing the square to solve the quadratic equation x 2 − 9 x − 8 = 0 x 2 −9x−8=0, which number would have to be added to "complete the square"?

Answers

Answer:

Add 81/4 to both sides.

Step-by-step explanation:

x^2 − 9x − 8 = 0

x^2 - 9x = 8

Take the coefficient of the x term: -9

Divide by 2: -9/2

Square it: 81/4

Add 81/4 to both sides.

100.331 divide 99.355​

Answers

Answer:

1.009823361

Step-by-step explanation:

Just divide like this:

[tex] \frac{100.331}{99.355} = 1.009853361[/tex]

What is the solution of log(4-3) = log(17-41)?
O4
O 5
O 15
O 20

Answers

Answer: Choice A) 4

Explanation:

The rule is that if log(A) = log(B), then A = B

Using this idea, we can then say,

log(t - 3) = log(17 - 4t)

t - 3 = 17 - 4t

t+4t = 17+3

5t = 20

t = 20/5

t = 4

The solution to the logarithmic equation is t = 5

What is Logarithm?

The power to which a number must be increased in order to obtain another number is known as the logarithm. A power is the opposite of a logarithm. In other words, if we subtract an exponentiation from a number by taking its logarithm

The properties of Logarithm are :

log A + log B = log AB

log A − log B = log A/B

log Aⁿ = n log A

Given data ,

Let the logarithmic equation be represented as A

Now , the value of A is

log ( t - 3 ) = log  (17 - 3t )   be equation (1)

On simplifying , we get

The bases of the logarithm are equal

So , the values are equal and therefore  

t - 3 = 17 - 3t

Adding 3t on both sides , we get

4t - 3 = 17

Adding 3 on both sides , we get

4t = 20

Divide by 4 on both sides , we get

t = 20 / 4

t = 5

Therefore , the value of t is 5

Hence , the logarithmic equation is solved

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What is the distance between (-5,-5) and (-9,-2)

Answers

Answer:

A (5)

Step-by-step explanation:

The distance is the slope/gradientIn the pythogaras theorem [tex]c^{2} = a^{2} + b^{2}[/tex],

        c represents the slope and a and b represent the two shorter sides of the right angled triangle ( x,y)

x = -9 - (-5 ) = -9 +5 = -4y = -2 - (-5) = -2 +5 = 3

       [tex]c^{2}[/tex] = [tex]-4^{2} + 3^{2}[/tex]

            = 16 + 9

             = 25,

therefore [tex]\sqrt{c^{2} }[/tex] = [tex]\sqrt{25}[/tex]

                   c = 5

                                                                                     

The resistors produced by a manufacturer are required to have an average resistance of 0.150 ohms. Statistical analysis of the output suggests that the resistances can be approximated by a normal distribution with known standard deviation of 0.005 ohms. We are interested in testing the hypothesis that the resistors conform to the specifications.

Requied:
a. Determine whether a random sample of 10 resistors yielding a sample mean of 0.152 ohms indicates that the resistors are conforming. Use alpha = 0.05.
b. Calculate a 95% confidence interval for the average resistance. How does this interval relate to your solution of part (a)?

Answers

Answer:

a) The p-value of the test is 0.2076 > 0.05, which means that the sample indicates that the resistors are conforming.

b) The 95% confidence interval for the average resistance is (0.147, 0.153). 0.152 is part of the confidence interval, which means that as the test statistic in item a), it indicates that the resistors are conforming.

Step-by-step explanation:

Question a:

The resistors produced by a manufacturer are required to have an average resistance of 0.150 ohms.

At the null hypothesis, we test if this is the average resistance, that is:

[tex]H_0: \mu = 0.15[/tex]

We are interested in testing the hypothesis that the resistors conform to the specifications.

At the alternative hypothesis, we test if it is not conforming, that is, the mean is different of 0.15, so:

[tex]H_1: \mu \neq 0.15[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.15 is tested at the null hypothesis:

This means that [tex]\mu = 0.15[/tex]

Sample mean of 0.152, sample of 10, population standard deviation of 0.005.

This means that [tex]X = 0.152, n = 10, \sigma = 0.005[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.152 - 0.15}{\frac{0.005}{\sqrt{10}}}[/tex]

[tex]z = 1.26[/tex]

P-value of the test and decision:

The p-value of the test is the probability of the sample mean differing from 0.15 by at least 0.152 - 0.15 = 0.002, which is P(|z| > 1.26), given by two multiplied by the p-value of z = -1.26.

Looking at the z-table, z = -1.26 has a p-value of 0.1038.

2*0.1038 = 0.2076

The p-value of the test is 0.2076 > 0.05, which means that the sample indicates that the resistors are conforming.

Question b:

We have to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a p-value of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 1.96\frac{0.005}{\sqrt{10}} = 0.003[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 0.15 - 0.003 = 0.147.

The upper end of the interval is the sample mean added to M. So it is 0.15 + 0.003 = 0.153.

The 95% confidence interval for the average resistance is (0.147, 0.153). 0.152 is part of the confidence interval, which means that as the test statistic in item a), it indicates that the resistors are conforming.

You are skiing down a mountain with a vertical height of 1250 feet. The distance that you ski as you go from the top down to the base of the mountain is 3350 feet. Find the angle of elevation from the base to the tep of the mountain. Round your answer to a whole number as necessary. ​

Answers

Step-by-step explanation:

here is the answer to your question

Y=square root of x compare to y= - square root of x how they differ and why

Answers

Answer:

Simply because x=y2 doesn't imply that y=

x

.

If the nominal rate of interest is 10% per annum and there is quarterly compounding, the effective rate of interest will be: a) 10% per annum b) 10.10 per annum c) 10.25%per annum d) 10.38% per annum​

Answers

9514 1404 393

Answer:

  d) 10.38%

Step-by-step explanation:

The multiplier for four quarters of quarterly compounding is ...

  (1 +10%/4)^4 = 1.025^4 = 1.103812890625

This is about 1 + 10.38%.

The effective rate of interest is about 10.38% per annum.

Graph the function g(x) = 3^x + 3 and give its domain and range using interval notation.

Answers

When a function is plotted on a graph, the domain and the range of the function are the x-coordinate and the y-coordinate respectively.

The domain and the range of the given function are:

Domain: [tex](-\infty,\infty)[/tex]

Range: [tex](3,\infty)[/tex]

 The given function is:

[tex]g(x) = 3^x + 3[/tex]

First, we plot the graph of g(x)

To do this, we need to generate values for x and g(x). The table is generated as follows:

[tex]x = 0 \to g(0) = 3^0 + 3 = 4[/tex]

[tex]x = 1 \to g(1) = 3^1 + 3 = 6[/tex]

[tex]x = 2 \to g(2) = 3^2 + 3 = 12[/tex]

[tex]x = 3 \to g(3) = 3^3 + 3 = 30[/tex]

[tex]x = 4 \to g(4) = 3^4 + 3 = 84[/tex]

The generated values in tabular form are:

[tex]\begin{array}{cccccc}x & {0} & {1} & {2} & {3} & {4} \ \\ g(x) & {4} & {6} & {12} & {30} & {84} \ \end{array}[/tex]

Refer to the attached image for graph of g(x)

To determine the domain, we simply observe the x-axis.

The curve stretches through the x-axis, and there are no visible endpoints on the axis.  This means that the curve starts from [tex]-\infty[/tex] to [tex]+\infty[/tex]

Hence, the domain of the function is: [tex](-\infty,\infty)[/tex]

To determine the range, we simply observe the y-axis.

The curve of g(x) starts at y = 3 on the y-axis and the curve faces upward direction.  This means that the curve of g(x) is greater than 3 on the y-axis.

Hence, the range of the function is: [tex](3,\infty)[/tex]

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Function: [tex]g(x) = 3^{x} + 3[/tex]. Domain: [tex]Dom \{g(x)\} = \mathbb{R}[/tex], Range: [tex]Ran \{g(x) \} = (3, +\infty)[/tex], respectively.

In Function Theory, the domain of a function [tex]f(x)[/tex] represents the set of values of the independent variable ([tex]x[/tex]), whereas the range of the function is the set of values of the dependent variable.

The Domain of the Function represents the set of values of [tex]x[/tex] (horizontal axis), whereas the Range it is the set of values of [tex]y[/tex] (vertical axis). After analyzing the existence of Asymptotes, we complement with graphic approaches and conclude where domain and range (in Interval notation) are.

Analytically speaking, the domain of exponential functions is the set of all real numbers and the range of [tex]g(x)[/tex] is any number between [tex]\lim_{x \to -\infty} g(x)[/tex] and [tex]\lim_{x \to +\infty} g(x)[/tex]. In a nutshell, we get the following conclusions in interval notation:

Domain: [tex]Dom \{g(x)\} = (-\infty, +\infty)[/tex], Range: [tex]Ran \{g(x) \} = (3, +\infty)[/tex]

Lastly, we proceed to complement this analysis by graphing function with the help of a graphing tool.

According to the image, domain and range coincides with outcomes from analytical approaches.

if qqq=90 what's qqqq+87​

Answers

Answer: [tex]90\sqrt[3]{90}+87[/tex]

Step-by-step explanation:

[tex]qqq=90\\q^3=90\\\sqrt[3]{q^3} =\sqrt[3]{90}\\q= \sqrt[3]{90}\\\\qqqq+87\\q^3q^1+87\\90\sqrt[3]{90}+87[/tex]

Molly and Lynn both set aside money weekly for their savings. Molly already has $650 set aside and adds $35 each week. Lynn already has $825 set aside but adds only $15 each week. Which inequality could they use to determine how many weeks, w, it will take for Molly’s savings to exceed Lynn’s savings?

Answers

FINAL ANSWER: D

Given : Molly and Lynn both set aside money weekly for their savings.

Molly already has $650 set aside and adds $35 each week.

Lynn already has $825 set aside but adds only $15 each week.

To Find :  inequality   to determine how many weeks, w, it will take for Molly’s savings to exceed Lynn’s savings

Solution:

Molly already has $650

adds $35 each week.

=> added in w  weeks  = 35w

After w weeks  = 650 + 35w

Lynn already has $825

adds $15 each week.

added in w  weeks  = 15w

After w weeks  = 825 + 15w

Molly’s savings to exceed Lynn’s savings

⇒ 650 + 35w >  825 + 15w

⇒  20w  >  175

⇒   4w >  35

⇒  w  >  35 /4

At least 9 weeks

Answer:

D

Step-by-step explanation:

First, to eliminate some answers you can figure out which way the sign should go. The question wants to know when Molly's savings will be larger so the sign should open towards her side of the equation. Since her savings are represented on the left the sign should be a greater than, >.

Then, figure out where the variables belong. The variable represents the number of weeks that have passed, so they should be multiplied by the number that is affected by the passing of weeks. This is the amount each person saves, aka the independent variable. So the "w" variable should be next to the 35 and 15.


Write an equation in slope-intercept form for the line with slope -3/2
and y-intercept 5.

Answers

Answer: y = -3/2x + 5

Step-by-step explanation:

Slope-intercept form: y = mx + b

m = slope = -3/2b = y-intercept = 5

y = -3/2x + 5

Answer:

y = -3/2x + 5 totally

Step-by-step explanation:

Need the value of P please

Answers

Answer:

B. 35°

Step-by-step explanation:

First, find the two interior angles that are adjacent to angles 90° and 125° respectively.

Thus:

Interior angle 1: 180° - 90° = 90° (linear pair)

Interior angle 2: 180° - 125° = 55° (linear pair)

P + 90° + 55° = 180° (sum of interior angles in a triangle)

P + 145° = 180°

Subtract 145° from each side

P = 180° - 145°

P = 35°

a. The lengths of pregnancies in a small rural village are normally distributed with a mean of 266 days and a standard deviation of 14 days.
In what range would you expect to find the middle 98% of most pregnancies?
Between_____ and___ .
If you were to draw samples of size 35 from this population, in what range would you expect to find the middle 98% of most averages for the lengths of pregnancies in the sample?
Between_________ and __________.
b. Engineers must consider the breadths of male heads when designing helmets. The company researchers have determined that the population of potential clientele have head breadths that are normally distributed with a mean of 6.9-in and a standard deviation of 0.9-in.
In what range would you expect to find the middle 95% of most head breadths?
Between ____________and ___________.
If you were to draw samples of size 45 from this population, in what range would you expect to find the middle 95% of most averages for the breadths of male heads in the sample?
Between____ and____ .
c. The lengths of pregnancies in a small rural village are normally distributed with a mean of 265.3 days and a standard deviation of 15.2 days.
In what range would you expect to find the middle 50% of most pregnancies?
Between ____and____ .
d. The lengths of pregnancies in a small rural village are normally distributed with a mean of 265 days and a standard deviation of 16 days.
In what range would you expect to find the middle 68% of most pregnancies?
Between _________and ___________.
If you were to draw samples of size 44 from this population, in what range would you expect to find the middle 68% of most averages for the lengths of pregnancies in the sample?
Between_____ and_____ .

Answers

Step-by-step explanation:

a.

mean = 266

sd = 14

cumulative probability = 0.01 so the standard score = -2.33 and 2.33 to the right and left

we find X-upper and X-lower

X-lower = 266-2.33*14 = 233.38

X-upper = 266+2.33*14 = 298.62

Between 233.38 and 298.62

we have sample size = 35

X-lower = 266-2.33*14/√35 = 260.49

X-upper = 266+2.33*14/√35 = 271.5

Between 260.49 and 271.5

b. cumulative probaility = 0.25

standard score = 1.96 to the right and left

x-lower = 6.9-1.96x0.9 = 5.14

x-upper = 6.9+1.96x0.9 = 8.66

Between 5.14 and 8.66

if sample size = 45

x-lower = 6.9-1.96*0.9/√45 = 6.64

x-upper = 6.9+1.96*0.9/√45 = 7.2

Between 6.64 and 7.2

c. standard scores would have cut off value at 0.67 and -0,67

x-lower = 265.3-0.67x15.2 = 255.12

x-upper = 265.3+0.67x15.2 = 275.48

Between 255.12 and 275.48

d. we will have critical values at 1.00 and -1.00

X-lower = 265-1x16 = 249

x-upper = 265+1x16 = 281

Between 249 and 281

with sample size = 44

x-lower = 265-1x16/√44 = 262.59

x-upper = 265+1x16/√44 = 267.41

Between 262.59 and 267.41

PLEASE HELP OR IM gonna FAILLLLLLLL!!!!!!!!

Answers

Answer:

C. 1/(4^10)

Step-by-step explanation:

Let's break it down: 4^-2 = 1/(4^2)(1/(4^2))^5 = (1^5)/(4^2)^5 = 1/(4^10)

what expression is equivalent to (-7²-x-5)-(3x²+x)

Answers

Answer:

-3x² - 2x - 54

Step-by-step explanation:

(-7²-x-5)-(3x²+x)

-7² - x - 5 - 3x² - x

-49 - x - 5 - 3x² - x

-3x² - x - x - 49 - 5

-3x² - 2x - 54

The graph represents two complex numbers, z1 and z2, as solid line vectors. Which points represent their complex conjugates?

Answers

Point A represents the complex conjugate z₁ and point L represents the complex conjugate of z₂ respectively

The reason the above values of the points of the complex conjugate are correct is as follows:

Definition:

The complex conjugate of a complex number is a complex number that

having equal magnitude in the real and imaginary part as the complex

number to which it is a conjugate, but the imaginary part of the complex

conjugate has an opposite sign to the original complex number

Graphically, the complex conjugate is a reflection of the

original complex number across the x-axis because the transformation for

a reflection of the point (x, y) across the x-axis is given as follows;

Preimage (x, y) reflected across the x-axis give the image (x, -y)

In a complex number, x + y·i. we have;

x = The real part

y = The imaginary part

The reflection of z₁(1, -2) across the x-axis gives the point A(1, 2), while the

reflection of z₂(6, -7) across the x-axis gives the point L(6, 7)

To summarize;

Point A(1, 2) is the reflection and therefore represents the complex

conjugate of z₁(1, -2) and point L(6, 7) is the reflection and therefore

represents the complex conjugate of z₂(6, -7)

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What is the height of spanning tree obtained from Wn by the breadth-first search, starting at the central vertex of Wn?

Answers

Answer:

The height of the spanning tree is one by the breadth-first search at the central vertex of Wn.

Step-by-step explanation:

The graph is connected and has a spanning tree where the tree can build using a depth-first search of the graph. Start with chosen vertex, the graph as the root, and root add vertices and edges such as each new edge is incident with vertex and vertices are not in path. If all vertices are included, it will do otherwise, move back to the next level vertex and start passing. It is for depth-first search. For breadth-first search, start with chosen vertex add all edges incident to a vertex. The new vertex is added and becomes the vertices at level 1 in the spanning tree, and each vertex at level 1 adds each edge incident to vertex and other vertex connected to the edge of the tree as long as it does not produce.

Need to know Anwser yes or no

Answers

Answer:

Reflective symmetry over the line y = 4 is No

Reflective symmetry over the line y = 1/7x + 3 is Yes

billy joe purchased a 60 gallon pool. at 1 pm he stared filling the pool at the rate of 3 gallons per hour. after 10 hours the horses started drinking the water at the rate of 1 gallon per hour. five hours after that he notices the animal and place a second hose in the pool which filled at the rate of 2 gallons per hour. at what time was the pool finally filled

Answers

Answer:

3*10=30 gallons after 10 hours

minus 1 gal/hr for 5 hours=25 gallons.

If the animals are still drinking, the pool is effectively filling at 1 gal/hr, 2-1, and it will take 35 more hours to fill.

If the animals aren't drinking, the pool will fill at 2 gal/hour and it will be full in 35/2 hours or 17.5 hours.

Step-by-step explanation:

One card is randomly selected from a deck of cards. Find the odds against drawing a black 10.

The odds against drawing a black ten are ___:___.
​(Simplify your​ answers.)

Answers

Answer:

25/26 or 26/27 depending on free hands.

The first is if you don't use jokers/free cards

There is 13 cards in a single set, and a single 10 card.

Two sets are black and two sets a red.

Hearts, Spades, Clubs, and Diamonds

There is only 2 black tens out of 52 or 54 cards, so we can set it up as

50/52 or 52/54 which is simplified to

25/26 or 26/27 depending on free hands.

Step-by-step explanation:

Q: Solve for x: 8x-2-5x=8
A. OX=13
B. OX=2 1/2
C. OX=3 1/3
D. OX=7

Answers

Answer:

c. 3 1/3

Step-by-step explanation:

8x-2-5x=8

3x=10

x=10/3=3 1/3

Answer:

x=[tex]3\frac{1}{3}[/tex]

Step-by-step explanation:

Hi there!

We want to find the value of x in this expression:

8x-2-5x=8

Our goal is to isolate x on one side

Combine like terms on the left side (add the terms with x together)

3x-2=8

Add 2 to both sides (-2+2=0)

3x-2=8

   +2  +2

__________

3x=10

Divide both sides by 3

x=[tex]\frac{10}{3}[/tex]

Simplify the improper fraction

x=[tex]3\frac{1}{3}[/tex]

Hope this helps!

The sum of two positive integers is 19 and the product is 48

Answers

Answer:

16 and 3

Step-by-step explanation:

Let x and y represent the positive integers. We know that

[tex]x + y = 19[/tex]

[tex]xy = 48[/tex]

Isolate the top equation for the x variable.

[tex]x = 19 - y[/tex]

Substitute into the second equation.

[tex](19 - y)y = 48[/tex]

[tex]19y - {y}^{2} = 48[/tex]

[tex] - {y}^{2} + 19y = 48[/tex]

[tex] - {y}^{2} + 19y - 48[/tex]

[tex](y - 16)(y - 3)[/tex]

So our values are

16 and 3.

Meena's family took a road trip to Niagara Falls. Meena slept through
the last 49% of the trip. If the total length of the trip was 500 miles, how many miles had they travelled when Meena fell asleep?

Answers

245 miles

49/100*500 i guess it's the answer

Answer: 255 miles

Explanation:

Total length of the trip = 500 miles

Then 49% = 49/100×500

= 245 miles

Therefore she slept for 245 miles

How many miles had they travelled when meena fell asleep

= 51%

= 51/100×500

= 255 miles

Or

500 - 245

= 255 miles

Answered by Gauthmath must click thanks and mark brainliest

For the function f(x) = x^2 + 4x -5 solve the following f(x)=0

Answers

That's a question about quadratic function.

Any quadratic function can be represented by the following form:

[tex]\boxed{f(x)=ax^2+bx+c}[/tex]

Example:

[tex]f(x)= -3x^2-9x+57[/tex] is a function where [tex]a=-3[/tex], [tex]b=-9[/tex] and [tex]c=57[/tex].

Okay, in our problem, we need to find the value of x when [tex]f(x)=0[/tex]. That's mean that the result of our function is equal to zero. Therefore, we have the quadratic equation below:

[tex]x^2+4x-5=0[/tex]

To solve a quadratic equation, we use the Bhaskara's formula. Do you remember the value of a, b and c? They going to be important right now. This is the Bhaskara's formula:

[tex]\boxed{x=\frac{-b\pm \sqrt{b^2-4ac} }{2a} }[/tex]

So, let's see the values of a, b and c in our equation and apply them in the Bhaskara's formula:

In [tex]x^2+4x-5=0[/tex] equation, [tex]a=1[/tex], [tex]b=4[/tex] and [tex]c=-5[/tex]. Let's replace those values:

[tex]x=\frac{-b\pm \sqrt{b^2-4ac} }{2a}[/tex]

[tex]x=\frac{-4\pm \sqrt{4^2-4\times1\times(-5)} }{2\cdot1}[/tex]

[tex]x=\frac{-4\pm \sqrt{16-(-20)} }{2}[/tex]

[tex]x=\frac{-4\pm \sqrt{16 + 20)} }{2}[/tex]

[tex]x=\frac{-4\pm \sqrt{36} }{2}[/tex]

[tex]x=\frac{-4\pm 6 }{2}[/tex]

From now, we have two possibilities:

To add:

[tex]x_1 = \frac{-4+6}{2} \\x_1=\frac{2}{2} \\x_1=1[/tex]

To subtract:

[tex]x_2=\frac{-4-6}{2} \\x_2=\frac{-10}{2} \\x_2=-5[/tex]

Therefore, the result of our problem is: [tex]x_1 = 1[/tex] and [tex]x_2=-5[/tex].

I hope I've helped. ^^

Enjoy your studies.  \o/

The angle θ between 5i-j+k & 2i-j+k is​

Answers

Step-by-step explanation:

Let,

[tex] \sf \vec{a} = 5 \hat{i} - \hat{j} + \hat{k} \\ \therefore \: \sf \: | \vec{a}| = \sqrt{ {5}^{2} + {( - 1)}^{2} + {1}^{2} } \\ = \sqrt{25 + 1 + 1} \\ = \sqrt{27} \\ \\ \sf \vec{b} = 2\hat{i} - \hat{j} + \hat{k} \\ \therefore \: \sf \: | \vec{b}| = \sqrt{ {2}^{2} + {( - 1)}^{2} + {1}^{2} } \\ = \sqrt{4 + 1 + 1} \\ = \sqrt{6} \\ \\\sf \: \vec{a}. \vec{b} = (5 \hat{i} - \hat{j} + \hat{k}).(2\hat{i} - \hat{j} + \hat{k}) \\ = 5 \times 2 + ( - 1) \times ( - 1) + 1 \times 1 \\ = 10 + 1 + 1 \\ = 12 \\ \\ \sf \: angle \: between \: \vec{a} \: and \: \vec{b} \: = \theta \\ \\ \: so \\ \sf \vec{a}. \vec{b} = | \vec{a}| . | \vec{b}| cos\theta \\ = > \sf \: cos \theta \: = \frac{ \vec{a}. \vec{b}}{ | \vec{a}| . | \vec{b}| } \\ = > cos \theta = \frac{12}{ \sqrt{27} \times \sqrt{6} } = 0.94 \\ = > \theta = {cos}^{ - 1} (0.94) \\ = > \green{\theta = 19.47 ^{ \circ} }[/tex]

When a constant force is applied to an object, the acceleration of the object varies inversely with its mass. When a certain constant force acts upon an object with mass 4 kg, the acceleration of the object is 13 m/s^2. When the same force acts upon another object, its acceleration is 2 m/s^2. What is the mass of this object?

Answers

Answer:

26 kg

Step-by-step explanation:

varies inversely :

y = k/x

acceleration = k/mass

13 = k/4

k= 52

---------------------

2 = k/mass

2 = 52/mass

mass = 26 kg

The isosceles triangle and rectangle have the same perimeter find the value of x

Answers

Answer:

x=15

Step-by-step explanation:

x+2+x+2+2x-2=9+8+9+8

2x+4=34

2x=30

x=15

At Dorcas's Hair Salon there are three hair stylists. 27% of the hair cuts are done by Martin, 30% are done by Jennifer, and 43% are done by Dorcas. Martin finds that when he does hair cuts, 6% of the customers are not satisfied. Jennifer finds that when she does hair cuts, 7% of the customers are not satisfied. Dorcas finds that when she does hair cuts, 3% of the customers are not satisfied. Suppose that a customer leaving the salon is selected at random. If the customer is not satisfied, what is the probability that their hair was done by Dorcas

Answers

Answer:

Dorcas's Hair Salon

If the customer is not satisfied, the probability that their hair was done by Dorcas is:

=  18.75%

Step-by-step explanation:

Number of hair stylists = 3

                                        Martin        Jennifer       Dorcas     Total

Percentage of haircuts

 done                               27%               30%            43%     100%

Percentage of dissatisfied

 customers                      6%                   7%               3%

Proportion of dissatisfied

 customers                    37.5% (6/16)    43.75% (7/16)   18.75% (3/16)

If the customer is not satisfied, the probability that their hair was done by Dorcas

=  18.75%

Find the missing length indicated

Answers

Answer:

x = 15

Step-by-step explanation:

x = √{(25-16)×25}

x = √(9×25)

x = √225

x = 15

Answered by GAUTHMATH

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