A simple random sample of 41 men from a normally distributed population results in a standard deviation of 10.7 beats per minute. The normal range of pulse rates of adults is typically given as 60 to 100 beats per minute. If the range rule of thumb is applied to that normal​ range, the result is a standard deviation of 10 beats per minute. Use the sample results with a 0.10 significance level to test the claim that pulse rates of men have a standard deviation equal to 10 beats per minute. Complete parts​(a) through​ (d) below.
a. Identify the null and alternative hypotheses.
b. Compute the test statistic; χ2 = ___ ​(Round to three decimal places as​ needed.)
c. Find the​ P-value; ​P-value = ____ ​(Round to four decimal places as​ needed.)
d. State the conclusion. (choose one from each ( x, y) set)
(Do not reject, Reject) Upper H0​, because the​ P-value is (greater than, less than, or equal to) the level of significance. There is
(sufficient, insufficient) evidence to warrant rejection of the claim that the standard deviation of​ men's pulse rates is equal to
10 beats per minute.

Answers

Answer 1

Answer:

H0 : σ²=10²

H1 : σ²>10²

χ² = 45.796

Pvalue = 0.2442

Do not reject H0 because Pvalue is greater Than significance level

There is insufficient evidence to warrant rejection of the claim that the standard deviation of​ men's pulse rates is equal to 10 beats per minute.

Step-by-step explanation:

Given that :

Sample size, n = 41

Sample standard deviation, s = 10.7

Population standard deviation, σ = 10

Significance level, α = 0.10

The Hypothesis :

H0 : σ²=10²

H1 : σ²>10²

Using the χ² test for population variance :

The test statistic, χ² = (n-1)*s²/σ²

χ² = (41 - 1) * 10.7²/ 10²

χ² = (40 * 114.49) / 100

χ² = 4579.6 / 100

χ² = 45.796

The Pvalue ;

df = n - 1 ; 41 - 1 = 40

Pvalue(45.796, 40) = 0.2442

Since Pvalue > α ; WE fail to reject H0

Do not reject H0 because Pvalue is greater Than significance level

There is insufficient evidence to warrant rejection of the claim that the standard deviation of​ men's pulse rates is equal to 10 beats per minute.


Related Questions

how many itegers from 15 to 85, inclusive are multibles of 8

Answers

Answer:

9

Step-by-step explanation:

First multiple of 8 in that range is 8(2)=16.

The last multiple of 8 in that range is 8(10)=80.

So we just need to find how many numbers there are between 2 and 10. inclusive.

10-2+1=9

It's also not that long to write out and count.

1-2

2-3

3-4

4-5

5-6

6-7

7-8

8-9

9-10

9 numbers there are

Multiply those 9 numbers by i you will have all multiples of 8 btw 15 and 85.

8(2)=16

8(3)=24

8(4)=32

8(5)=40

8(6)=48

8(7)=56

8(8)=64

8(9)=72

8(10)=80

Please I need help :(

Answers

Answer:

A. x-2y-3z = 1/2

Step-by-step explanation:

yess.. if you take solve every equation then you will get same equation from all the equations

What is the equation of a circle with center (1, -4) and radius 2?

Answers

Answer:

(x-1)^2 + (y+4)^2 = 4

Step-by-step explanation:

The equation for a circle is given by

(x-h)^2 + (y-k)^2 = r^2 where (h,k) is the center and r is the radius

(x-1)^2 + (y- -4)^2 = 2^2

(x-1)^2 + (y+4)^2 = 4

What is the simple interest rate if $51.67 in interest is earned on a deposit of $1377.53 in one year?

Answers

Answer:

2666.01%

Step-by-step explanation:

Intrest=(PA)*I*T

1377.53=51.67*I*1

I=26.6601=2666.01%

how to solve this trig

Answers

Hi there!

To find the Trigonometric Equation, we have to isolate sin, cos, tan, etc. We are also given the interval [0,2π).

First Question

What we have to do is to isolate cos first.

[tex] \displaystyle \large{ cos \theta = - \frac{1}{2} }[/tex]

Then find the reference angle. As we know cos(π/3) equals 1/2. Therefore π/3 is our reference angle.

Since we know that cos is negative in Q2 and Q3. We will be using π + (ref. angle) for Q3. and π - (ref. angle) for Q2.

Find Q2

[tex] \displaystyle \large{ \pi - \frac{ \pi}{3} = \frac{3 \pi}{3} - \frac{ \pi}{3} } \\ \displaystyle \large \boxed{ \frac{2 \pi}{3} }[/tex]

Find Q3

[tex] \displaystyle \large{ \pi + \frac{ \pi}{3} = \frac{3 \pi}{3} + \frac{ \pi}{3} } \\ \displaystyle \large \boxed{ \frac{4 \pi}{3} }[/tex]

Both values are apart of the interval. Hence,

[tex] \displaystyle \large \boxed{ \theta = \frac{2 \pi}{3} , \frac{4 \pi}{3} }[/tex]

Second Question

Isolate sin(4 theta).

[tex] \displaystyle \large{sin 4 \theta = - \frac{1}{ \sqrt{2} } }[/tex]

Rationalize the denominator.

[tex] \displaystyle \large{sin4 \theta = - \frac{ \sqrt{2} }{2} }[/tex]

The problem here is 4 beside theta. What we are going to do is to expand the interval.

[tex] \displaystyle \large{0 \leqslant \theta < 2 \pi}[/tex]

Multiply whole by 4.

[tex] \displaystyle \large{0 \times 4 \leqslant \theta \times 4 < 2 \pi \times 4} \\ \displaystyle \large \boxed{0 \leqslant 4 \theta < 8 \pi}[/tex]

Then find the reference angle.

We know that sin(π/4) = √2/2. Hence π/4 is our reference angle.

sin is negative in Q3 and Q4. We use π + (ref. angle) for Q3 and 2π - (ref. angle for Q4.)

Find Q3

[tex] \displaystyle \large{ \pi + \frac{ \pi}{4} = \frac{ 4 \pi}{4} + \frac{ \pi}{4} } \\ \displaystyle \large \boxed{ \frac{5 \pi}{4} }[/tex]

Find Q4

[tex] \displaystyle \large{2 \pi - \frac{ \pi}{4} = \frac{8 \pi}{4} - \frac{ \pi}{4} } \\ \displaystyle \large \boxed{ \frac{7 \pi}{4} }[/tex]

Both values are in [0,2π). However, we exceed our interval to < 8π.

We will be using these following:-

[tex] \displaystyle \large{ \theta + 2 \pi k = \theta \: \: \: \: \: \sf{(k \: \: is \: \: integer)}}[/tex]

Hence:-

For Q3

[tex] \displaystyle \large{ \frac{5 \pi}{4} + 2 \pi = \frac{13 \pi}{4} } \\ \displaystyle \large{ \frac{5 \pi}{4} + 4\pi = \frac{21 \pi}{4} } \\ \displaystyle \large{ \frac{5 \pi}{4} + 6\pi = \frac{29 \pi}{4} }[/tex]

We cannot use any further k-values (or k cannot be 4 or higher) because it'd be +8π and not in the interval.

For Q4

[tex] \displaystyle \large{ \frac{ 7 \pi}{4} + 2 \pi = \frac{15 \pi}{4} } \\ \displaystyle \large{ \frac{ 7 \pi}{4} + 4 \pi = \frac{23\pi}{4} } \\ \displaystyle \large{ \frac{ 7 \pi}{4} + 6 \pi = \frac{31 \pi}{4} }[/tex]

Therefore:-

[tex] \displaystyle \large{4 \theta = \frac{5 \pi}{4} , \frac{7 \pi}{4} , \frac{13\pi}{4} , \frac{21\pi}{4} , \frac{29\pi}{4}, \frac{15 \pi}{4} , \frac{23\pi}{4} , \frac{31\pi}{4} }[/tex]

Then we divide all these values by 4.

[tex] \displaystyle \large \boxed{\theta = \frac{5 \pi}{16} , \frac{7 \pi}{16} , \frac{13\pi}{16} , \frac{21\pi}{16} , \frac{29\pi}{16}, \frac{15 \pi}{16} , \frac{23\pi}{16} , \frac{31\pi}{16} }[/tex]

Let me know if you have any questions!

y=4.5x+13.45 y=6x-4.55

Answers

Step-by-step explanation:

Solve for the first variable in one of the equations, then substitute the result into the other equation.

Point Form:

(

12

,

67.45

)

Equation Form:

x

=

12

,

y

=

67.45

Which of the following numbers has the greatest value?
89 3/4
66 1/2
55 2/3
74 1/4
106 5/6

Answers

Answer:

106 5/6

Step-by-step explanation:

55 < 66 < 74 < 89 < 106

the fractions are irrelevant because the whole numbers are all different

The greatest of the numbers will be 106 5/6 since 106 is greater than the rest of the integers present in the mixed fractions.

Finding greatest value in a sequence

The greatest value is the highest value in a given set of number.

Given the following numbers

89 3/4

66 1/2

55 2/3

74 1/4

106 5/6

The greatest of the numbers will be 106 5/6 since 106 is greater than the rest of the integers present in the mixed fractions.

Learn more on mixed fractions here: https://brainly.com/question/414559

#SPJ6

Find the length of the missing sides

Answers

Answer:

f = 10

g = 2 sqrt(3)

h = 20

Step-by-step explanation:

The short leg is opposite the smaller angle so it is f

The longer leg is opposite the larger angle so it is g

The hypotenuse is opposite the right angle so it is 20

We know f = x

g = x sqrt(3)

h = 2x = 20

2x = 20  so x = 10

f = 10

g = 2 sqrt(3)

h = 20

Complete the statement below. A Type II Error is made... Choose the correct answer below. A. A Type II Error is made when​ there's not enough evidence to reject the null hypothesis and the null hypothesis is true. B. A Type II Error is made when​ there's evidence to reject the null​ hypothesis, but the null hypothesis is true. C. A Type II Error is made when​ there's not enough evidence to reject the null​ hypothesis, but the null hypothesis is not true. D. A Type II Error is made anytime we do not reject the null hypothesis.

Answers

I think it’s d I believe

A note card company has found that the marginal cost per card of producing x note cards is given by the function below, where C'(x) is the
marginal cost, in cents, per card. Find the total cost of producing 900 cards, disregarding any fixed costs.
C'(x) = -0.05x + 77, for x S 1000
The total cost is
cents

Answers

Answer:

49,050cents

Step-by-step explanation:

Given the expression for calculating the marginal cost per card of producing x note cards expressed as

C'(x) = -0.05x + 77

On intergrating the marginal cost, we will get the total cost

C(x) =  -0.05x²/2 + 77x

Substitute x = 900 into the resulting expression

C(900) =  -0.05(900)²/2 + 77(900)

C(900) = -20,250+69,300

C(900) = 49,050

Hence the total costs in cents is 49,050cents

13. 30 of the 100 iPads in an inventory are known to be cracked. What
is the probability you randomly select one that is not cracked?

Answers

Answer:

7/10 or 0.7

Step-by-step explanation:

a probability is always the ratio of possible cases over all cases.

"all cases" here is 100.

possible cases are all iPads not cracked in the inventory = 70 (because 30 are cracked, that leaves 100-30=70 not cracked).

so, the probability to select a non-cracked unit is

70/100 or simplified 7/10 (or 0.7)

solve x^3-7x^2+7x+15​

Answers

Step-by-step explanation:

\underline{\textsf{Given:}}

Given:

\mathsf{Polynomial\;is\;x^3+7x^2+7x-15}Polynomialisx

3

+7x

2

+7x−15

\underline{\textsf{To find:}}

To find:

\mathsf{Factors\;of\;x^3+7x^2+7x-15}Factorsofx

3

+7x

2

+7x−15

\underline{\textsf{Solution:}}

Solution:

\textsf{Factor theorem:}Factor theorem:

\boxed{\mathsf{(x-a)\;is\;a\;factor\;P(x)\;\iff\;P(a)=0}}

(x−a)isafactorP(x)⟺P(a)=0

\mathsf{Let\;P(x)=x^3+7x^2+7x-15}LetP(x)=x

3

+7x

2

+7x−15

\mathsf{Sum\;of\;the\;coefficients=1+7+7-15=0}Sumofthecoefficients=1+7+7−15=0

\therefore\mathsf{(x-1)\;is\;a\;factor\;of\;P(x)}∴(x−1)isafactorofP(x)

\mathsf{When\;x=-3}Whenx=−3

\mathsf{P(-3)=(-3)^3+7(-3)^2+7(-3)-15}P(−3)=(−3)

3

+7(−3)

2

+7(−3)−15

\mathsf{P(-3)=-27+63-21-15}P(−3)=−27+63−21−15

\mathsf{P(-3)=63-63}P(−3)=63−63

\mathsf{P(-3)=0}P(−3)=0

\therefore\mathsf{(x+3)\;is\;a\;factor}∴(x+3)isafactor

\mathsf{When\;x=-5}Whenx=−5

\mathsf{P(-5)=(-5)^3+7(-5)^2+7(-5)-15}P(−5)=(−5)

3

+7(−5)

2

+7(−5)−15

\mathsf{P(-5)=-125+175-35-15}P(−5)=−125+175−35−15

\mathsf{P(-5)=175-175}P(−5)=175−175

\mathsf{P(-5)=0}P(−5)=0

\therefore\mathsf{(x+5)\;is\;a\;factor}∴(x+5)isafactor

\underline{\textsf{Answer:}}

Answer:

\mathsf{x^3+7x^2+7x-15=(x-1)(x+3)(x+5)}x

3

+7x

2

+7x−15=(x−1)(x+3)(x+5)

\underline{\textsf{Find more:}}

Find more:

Problem 2 find m<GEF​

Answers

Answer:

m<GEF = 66°

Step-by-step explanation:

(72+60)/2

= 132/2

= 66

Answered by GAUTHMATH

ty
This graph shows a portion of an even function.
Use the graph to complete the table of values.
6
f(x)
-1
4
-3
-5
-6
2
DONE
2
4.
6

Answers

Answers:

first box = 1second box = 1third box = 3fourth box = 3

Refer to the graph below.

==========================================================

Explanation:

If f(x) is an even function, then f(-x) = f(x) for all x in the domain.

What this means is that we have symmetry about the y axis. We can reflect that given curve over the y axis to generate the missing left side.

The graph shows that (1,1) is on the orange curve. It reflects over to (-1,1). This means 1 goes in the first box.

Use the rule [tex](x,y) \to (-x,y)[/tex] to apply a y axis reflection. We simply just change the sign of the x coordinate from positive to negative, while keeping the y coordinate the same.

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

We can also see that (3,1) is also on the orange curve. It reflects over to (-3, 1) using that rule mentioned earlier.

1 goes in the second box

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

The graph your teacher gave you shows that if we plugged in x = 5, then we get y = 3. In other words, the point (5,3) is on the orange graph.

It reflects over to (-5, 3) to show that x = -5 leads to the output y = 3

3 goes in the third box

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

Lastly, the point (6,3) reflects to (-6,3) when reflecting over the y axis.

3 goes in the fourth box.

See the graph below.

If you apply the changes below to the absolute value parent function F(x)= |x|, What is the new function? Shift 5 units to the left, shift 4 units down.

Answers

F(x)=|x+5|-4

An absolute value function is in the form F(x)=|x-h|+k where the graph is moved h units right and k units left. In this problem, h=-5 and k=-4.

PLEASE I NEED A REAL ANWSER NO LIES

Part A: The area of a square is (9a2 − 24a + 16) square units. Determine the length of each side of the square by factoring the area expression completely. Show your work. (5 points)

Part B: The area of a rectangle is (25a2 − 36b2) square units. Determine the dimensions of the rectangle by factoring the area expression completely. Show your work. (5 points)

Answers

Answer:

(3a - 4 )^2

Step-by-step explanation:

(9a^2-24a+16)=(3a - 4 )^2

Therefore the length of each side of the square is (3a - 4 )^2

Answer:

Part A: (3a - 4)^2

Part B: (5a + 6b)(5a - 6b)

Step-by-step explanation:

Part A:

It looks like this is the square of a binomial. Now we check it.

9a^2 is the square of 3a.

16 is the square of 4 and of -4.

Check the middle term:

2 * 3a * 4 = 24a

2 * 3a * (-4) = -24a

Since we get -24a when we use 4, the second term of the binomial is 4.

Answer:

9a^2 - 24a + 16 = (3a - 4)^2

Part B:

25a^2 − 36b^2

This is a two-term polynomial. The two terms are perfect squares and there is a subtraction sign between them, so this is the difference of two squares. The difference of two squares factors into the product of a sum and a difference.

25a^2 is the square of 5a.

36b^2 is the square of 6b.

25a^2 − 36b^2 = (5a + 6b)(5a - 6b)

A physical trainer decides to collect data to see if people are actually weight changing weight during the shelter in place. He believes there will not be a meaningful change in weight due to the shelter in place order. He randomly chooses a sample of 30 of his clients. From each client, he records their weight before the shelter in place order, and again 10 days after the order. A summary of the data is below.
The trainer claims, "on average, there is no difference in my clients' weights before and after the shelter in place order." Select the pair of hypotheses that are appropriate for testing this claim.
H0: µd = 0
H1: µd < 0 (claim)
H0: µd = 0 (claim)
H1: µd ≠ 0
H0: µd ≠ 0 (claim)
H1: µd = 0
H0: µd = 0 (claim)
H1: µd > 0
H0: µd = 0
H1: µd > 0 (claim)
H0: µd = 0
H1: µd ≠ 0 (claim)
H0: µd = 0 (claim)
H1: µd < 0
H0: µd ≠ 0
H1: µd = 0 (claim)
b) Select the choice that best describes the nature and direction of a hypothesis test for this claim.
This is a right-tail t-test for µd.
This is a right-tail z-test for µd.
This is a two-tail t-test for µd.
This is a two-tail z-test for µd.
This is a left-tail t-test for µd.
This is a left-tail z-test for µd.
c) Find the standardized test statistic for this hypothesis test. Round your answer to 2 decimal places.
d) Find the P-value for this hypothesis test. Round your answer to 4 decimal places.
e) Using your previous calculations, select the correct decision for this hypothesis test.
Fail to reject the alternative hypothesis.
Reject the alternative hypothesis.
Fail to reject the claim.
Reject the claim.
Fail to reject the null hypothesis.
Reject the null hypothesis.
f) Consider the following statements related to the trainer's claim. Interpret your decision in the context of the problem (ignoring the claim) and interpret them in the context of the claim.

Answers

Answer:

H0: µd = 0 (claim)

H1: µd ≠ 0

This is a two-tail t-test for µd

Step-by-step explanation:

This is a paired (dependent) sample test, with its hypothesis is written as :

H0: µd = 0

H1: µd ≠ 0

From the equality sign used in the hypothesis declaration, a not equal to ≠ sign in the alternative hypothesis is used for a two tailed t test

The data isn't attached, however bce the test statistic cannot be obtained. However, the test statistic formular for a paired sample is given as :

T = dbar / (Sd/√n)

dbar = mean of the difference ; Sd = standard deviation of the difference.

The gate of a stadium ha two pillars each of height 10ft.with four visible lateral faces and 3ft*3ft bases .the top of eaxh pillar has combined pyaramid of height2ft.If the combined structures of both pillars and pyramid are painted at the rate of rs 80 persq.ft.calcuate the total cost of painting.

Answers

The pillars and the pyramids in the stadium gate means that we have to calculate the area of the items that make up the gate one after the other. At the end of the calculation, the calculated areas are then added up.

The total cost of painting is Rs.21344

First, we calculate the area of 1 side of 1 pillar using:

[tex]A = Height * Base[/tex]

Where

[tex]Height = 10ft[/tex] --- Height of the pillar

[tex]Base = 3ft[/tex] --- Base of the pillar

So:

[tex]A = 10ft * 3ft[/tex]

[tex]A = 30ft^2[/tex]

The area of the 4 sides of the pillar is:

[tex]A_2 = 4 * A[/tex] --- i.e. 4 multiplied by the area of 1 side

[tex]A_2 = 4 * 30ft^2[/tex]

[tex]A_2 = 120ft^2[/tex]

The area of the 2 pillars is:

[tex]Area_1 = 2 * A_2[/tex] --- i.e. 2 multiplied by the area of 1

[tex]Area_1 = 2 * 120ft^2[/tex]

[tex]Area_1 = 240ft^2[/tex]

Because one part of the pyramid won't be visible, we calculate the area of the pyramid using:

[tex]Area = lw + l\sqrt{(w/2)^2 + h^2} + w\sqrt{(l/2)^2 + h^2}[/tex]

Where:

[tex]h = 2[/tex] -- the height

[tex]l = w = 3[/tex] --- the base of the pillar is the length & width of the pyramid.

So, we have:

[tex]Area = 3\sqrt{(2/2)^2 + 2^2} + 3\sqrt{(2/2)^2 + 2^2}[/tex]

[tex]Area = 3\sqrt{1 + 4} + 3\sqrt{1 + 4}[/tex]

[tex]Area = 3\sqrt{5} + 3\sqrt{5}[/tex]

[tex]Area = 6\sqrt{5}[/tex]

For the two pyramids, the area is:

[tex]Area_2 = 2 * 6\sqrt 5[/tex] -- 2 multiplied by area of 1

[tex]Area_2 = 12\sqrt 5[/tex]

[tex]Area_2 = 26.8[/tex]

So, the total area to be painted is:

[tex]Total = Area_1 + Area_2[/tex] --- the sum of the area of the pillars and the pyramids

[tex]Total = 240+26.8[/tex]

[tex]Total = 266.8ft^2[/tex]

The unit cost of paint is:

Rate = Rs80 per sq.ft

The total cost of painting is:

[tex]Cost = 80 * 266.8[/tex]

[tex]Cost = Rs.21344[/tex]

Hence, the total cost of painting is Rs.21344.

Read more at:

https://brainly.com/question/14320476

The answer the the question pictured

Answers

Answer:

x-1/2x-3

Step-by-step explanation:

be happy bro this is your perfect answer

scientist has two solutions, which she has labeled solution a and solution b. solution a is 60% salt and solution b is 85% salt. she wants to obtain 140 ounces of mixture that is 80% salt. How many ounces of each solution should she use?

Answers

Answer:

We have 60% salt and 85% salt solutions and we need 140 ounces of a solution that is 80% salt.

We set up 2 equations:

A) x + y = 140

B) .60x + .85y = .80 * 140

Multiply equation A) by -.60

A) -.60x -.60y = -84  then we add this to B)

B) .60x + .85y = 112

.25y = 28

y = 112 ounces of 85% salt

x = 28 ounces of 60% salt.

Double Check

112 * .85 = 95.2 AND 28 * .60 = 16.80

95.2 + 16.80 = 112

and 112/140 = 80 per cent!!

Source: http://www.1728.org/mixture.htm

 

Step-by-step explanation:

what is the value of sum of 18 and 3 time the difference of 9 and 5 divided by 2 is subtracted from 30 ?​
if u give right answer i will mark u as a brainlist

Answers

Answer:

12

Step-by-step explanation:

(18+3)=21

(9-5)=4

4x21=84

84/2=42

42-30=12

Answer:

12

Step-by-step explanation:

((18+3)x(9-5))/2-30

=((21)x(4))/2-30

=(84)/2-30

=42-30

=12

A health club sold ten memberships in one week for total of $3000. If male memberships cost $300 and female memberships cost $300, then how many male memberships and how female memberships were sold?

Answers

Answer:

Step-by-step explanation:

The reason you haven't gotten an answer to this is because in its current formatting, there is no answer. Here's what I mean:

The first equation is going to be concerning the NUMBER of memberships sold, where m is male and f is female. The total number of memberships was 10:

m + f = 10

Now for the money equation. The total amount of money made from that number of memberships was 3000, where male memberships cost $300 and so do the female memberships, giving us an equation of

300m + 300f = 3000

Go back to the first equation and solve for either m or f. I solved for m in terms of f:

m = 10 - f and sub that into the second equation for m to get:

300(10 - f) + 300f = 3000 and

3000 - 300f + 300f = 3000. Here is where you find the problem. The -300f and the 300f cancel each other out, leaving you with the fact that

3000 = 3000 which it does, but it doesn't give us any viable answer.

I would have to say that since we can't do math on this, that the most credible answer you'll find is that the same number of male and female memberships were sold because 5 male memberships cost $1500 (5 memberships at $300 a piece is $1500) and 5 female memberships also cost $1500.

1500 + 1500 = 3000

welp I am getting graded for this​

Answers

Answer:

it is summer how do y'all still have school,like don't they give y'all a break

can someone please help with answer and explanation

Answers

9514 1404 393

Answer:

  (x, y) = (3, 12)

Step-by-step explanation:

The first step in any problem solving is to look at the problem. Here, we see that the first equation can be reduced to standard form by dividing it by 2. This would give both terms a coefficient of 1.

We see that the second equation already has a variable with a coefficient of 1.

When solving a system by substitution, it can save some effort if you start by finding a variable with a coefficient of 1 or -1. Since we see that in the second equation, we choose to solve the second equation for y:

  y = 4x . . . . . . . add 4x to both sides of the second equation

Now, we have an expression for y that we can substitute into the first equation.

  2x +2(4x) = 30 . . . . substitute for y

  10x = 30 . . . . . . . . simplify

  x = 3 . . . . . . . . . . divde by 10

  y = 4(3) = 12 . . . . . find y using y=4x

The solution is (x, y) = (3, 12).

__

Additional comment

I doesn't matter what variable gets substituted. The purpose of the exercise is to reduce the number of variables in the equation. Here, we start with an equation that has 2 variables. Substituting for one of them gives an equation with only one variable, a lot easier to solve.

You don't have to find an expression for the "bare" variable. We could solve the second equation for 2x, for example: 2x = y/2, then substitute for 2x in the first equation: y/2 +2y = 30   ⇒   y = (2/5)(30) = 12. Or, we could solve the first equation for 2x and substitute into the second: 2x=30-2y, y-2(2x) = 0 ⇒ y-2(30-2y) = 0 ⇒ y = 60/5 = 12.

The substitution property of equality says you can make any substitution of equal values anywhere. "butter = margarine" means you can substitute butter for margarine, or vice versa, wherever you may wish.

can somebody help with this please

Answers

Answer:

"D"

Step-by-step explanation:

just add the two functions

5x^2 - 8x^2 = -3x^2 etc

What is the length of de?

Answers

Answer: length of DE = 18

Step-by-step explanation:

Since the angles of these two triangles are the same, we can assume that they are similar triangles. To solve for a missing side of a triangle that is similar, you can set up a proportion:

[tex]\frac{27}{15}=\frac{x}{10}[/tex]

To solve for x (the missing length), you would do:

27 × 10 ÷ 15 = 18

You can set up the proportion in any way between the two triangles as long as the two sides correspond to each other. For example, you could have also used the following proportion to solve for x:

[tex]\frac{x}{27} =\frac{10}{15}[/tex]

When you solve for x using this proportion, you would get the same value for x:

10 × 27 ÷ 15 = 18

Average person who drives car in United States drives 15, 350 miles which is 50% more than an average driver in Europe. We assume that the number of yearly miles by U.S. drivers is approximately a normal random variable of standard deviation of 4200 miles. Calculate percent of drivers who traveled between 10,000 to 12,000 miles in a year.

Answers

Answer:

7,675

that is your answer



Why is the value of -9 is not-3

Answers

Answer:

Because it's a negative.

Step-by-step explanation:

The value of a positive number is still a positive number.

A normal distribution has a mean of 15 and a standard deviation of 2. Find the value that corresponds to the 75th
percentile. Round your answer to two decimal places.
N
0.00
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.5
0.6915
0.6950
0.6985
0.7019
0.7054
0.7088
0.7123
0.7157
0.7190
0.7224
0.6 0.7257
0.7291
0.7324
0.7357
0.7389 0.7422
0.7454
0.7486
0.7517
0.7549
0.7 0.7580
0.7611
0.76420.7673
0.7704
0.7734
0.7764
0.7794
0.7823
0.7852
0.8
0.7881
0.7910
0.7939
0.7967
0.7995
0.8023
0.8051
0.8078
0.8106
0.8133

Answers

I am sorry, I am so confused
I wish I could help

someone help me pls i need to pass summer school

Answers

16 to the 0 power 16 to the 0 power 16 to the 0 power 16 to the 0 power 16 to the 0 power

Answer:

A

Step-by-step explanation:

The be the inverse function the domain {4,5,6,7} becomes the range and the range {14,12,10,8} becomes the domain

14 → 4

12 →5

10 →6

8 →7

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