Answer:
The point estimate is 5,617.
The margin of error of a confidence interval for the difference between the two population means is 454.18386 .
The 98% confidence interval for the difference between the two population means is (5163, 6071).
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Compound 1:
127 brakes, average brake life of 42,814 miles, population standard deviation of 1819 miles. This means that:
[tex]\mu_1 = 42814[/tex]
[tex]s_1 = \frac{1819}{\sqrt{127}} = 161.41[/tex]
Compound 2:
163 brakes, average brake life of 37,197 miles, population standard deviation of 1401 miles. This means that:
[tex]\mu_2 = 37197[/tex]
[tex]s_2 = \frac{1401}{\sqrt{163}} = 109.73[/tex]
Distribution of the difference:
[tex]\mu = \mu_1 - \mu_2 = 42814 - 37197 = 5617[/tex]
The point estimate is 5,617.
[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{161.41^2 + 109.73^2} = 195.18[/tex]
Confidence interval
The confidence interval is:
[tex]\mu \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = zs[/tex]
98% confidence level
So [tex]\alpha = 0.02[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.02}{2} = 0.99[/tex], so [tex]Z = 2.327[/tex].
Margin of error:
[tex]M = zs = 195.18*2.327 = 454.18386 [/tex]
The margin of error of a confidence interval for the difference between the two population means is 454.18386 .
For the confidence interval, as we round to the nearest whole number, we round it 454. So
The lower bound of the interval is:
[tex]\mu - zs = \mu - M = 5617 - 454 = 5163[/tex]
The upper bound of the interval is:
[tex]\mu + zs = \mu + M = 5617 + 454 = 6071[/tex]
The 98% confidence interval for the difference between the two population means is (5163, 6071).
Write an equation in slope-intercept form for the line with slope -3/2
and y-intercept 5.
Answer: y = -3/2x + 5
Step-by-step explanation:
Slope-intercept form: y = mx + b
m = slope = -3/2b = y-intercept = 5y = -3/2x + 5
Answer:
y = -3/2x + 5 totally
Step-by-step explanation:
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?
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
a fair coin is flipped. if the flip results in a head, then a fruit is selected from a basket containing 8 apples, 2 bananas, and 6 cantaloups. if the flip results in a tail, then a fruit is selected from a basket containing 6 apples and 4 bananas. what is the probability that the flip resulted in tails, given that the fruit selexted is a banana g
Solution :
We have given two baskets :
[tex]$H_1$[/tex] : 8 apples + 2 bananas + 6 cantaloupes = 16 fruits
[tex]$H_2$[/tex] : 6 apples + 4 bananas = 10 fruits
A fair coin is made to flipped. If the [tex]\text{flip}[/tex] results is head, then the fruit is selected from a basket [tex]$H_1$[/tex].
If the flip results in tail, then the fruit is selected from the basket [tex]$H_2$[/tex].
Probability of head P(H) = [tex]1/2[/tex]
Probability of tail P(T) = [tex]1/2[/tex]
if given event is :
B = selected fruit is BANANA
We have to calculate : P(T|B)
Probability of banana if the flip results is head P(B|H) = [tex]$\frac{2}{16}$[/tex]
Probability of banana if the flip results is tail P(B|T) = [tex]$\frac{4}{10}$[/tex]
From the Bayes' theorem :
Probability of flip results is tail when selected fruit is BANANA.
[tex]$P(T|B) = \frac{P(B|T)\ P(T)}{P(B|T) \ P(T) + P(B|H)\ P(H)}$[/tex]
[tex]$=\frac{\frac{4}{10} \times \frac{1}{2}} {\frac{4}{10} \times \frac{1}{2} + \frac{2}{16} \times \frac{1}{2}}$[/tex]
[tex]$=\frac{\frac{1}{5}}{\frac{1}{5}+\frac{1}{16}}$[/tex]
[tex]$=\frac{\frac{1}{5}}{\frac{21}{80}}$[/tex]
[tex]$=\frac{16}{21}$[/tex]
∴ [tex]$P(\ T|B\ )=\frac{16}{21}$[/tex]
Exhibit 10-7 In order to estimate the difference between the average hourly wages of employees of two branches of a department store, two independent random samples were selected and the following statistics were calculated. Downtown Store North Mall Store Sample size 25 20 Sample mean $9 $8 Sample standard deviation $2 $1 Refer to Exhibit 10-7. A 95% interval estimate for the difference between the two population means is _____. Selected Answer: b. .071 to 1.928
Answer:
[tex]E(x)=1[/tex]
Step-by-step explanation:
From the question we are told that:
Sample mean 1 [tex]\=x_1=$9[/tex]
Sample mean 1 [tex]\=x_2=$8[/tex]
Sample standard deviation 1 [tex]\sigma_1 = $2[/tex]
Sample standard deviation 1 [tex]\sigma_2 = $1[/tex]
Generally the equation for Point estimate is mathematically given by
[tex]E(x)=\=x_1-\=x_2[/tex]
[tex]E(x)=9-8[/tex]
[tex]E(x)=1[/tex]
a group of workers can plant 3/5 acres in 5/6 days. what is the unit rate per day?
Answer:
Workers can plant 0.72 acres per day.
Write the solution for x+5≤8 x + 5 ≤ 8 in set notation
9514 1404 393
Answer:
{x ∈ ℝ | x ≤ 3}
Step-by-step explanation:
Subtracting 5 from both sides, we see the solution is ...
x ≤ 3
In set notation, this can be written ...
{x ∈ ℝ | x ≤ 3}
The sum of two positive integers is 19 and the product is 48
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.
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
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%
100.331 divide 99.355
Answer:
1.009823361
Step-by-step explanation:
Just divide like this:
[tex] \frac{100.331}{99.355} = 1.009853361[/tex]
what expression is equivalent to (-7²-x-5)-(3x²+x)
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
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
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:
The graph represents two complex numbers, z1 and z2, as solid line vectors. Which points represent their complex conjugates?
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)
Learn more about complex numbers here;
https://brainly.com/question/20365080
Insurance companies are interested in knowing the population percent of drivers who always buckle up before riding in a car. They randomly survey 401 drivers and find that 294 claim to always buckle up. Construct a 90% confidence interval for the population proportion that claim to always buckle up. Use interval notation, for example, [1,5].
Answer:
[0.6969, 0.7695]
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
They randomly survey 401 drivers and find that 294 claim to always buckle up.
This means that [tex]n = 401, \pi = \frac{294}{401} = 0.7332.
90% confidence level
So [tex]\alpha = 0.1[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].
The lower limit of this interval is:
[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.7332 - 1.645\sqrt{\frac{0.7332*0.2668}{401}} = 0.6969[/tex]
The upper limit of this interval is:
[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.7332 + 1.645\sqrt{\frac{0.7332*0.2668}{401}} = 0.7695[/tex]
The 90% confidence interval for the population proportion that claim to always buckle up is [0.6969, 0.7695]
show that the line x-y+2=0 and the line joining the points (4,6) and (10,12) are parallel to each other
x-y+2=0
-y= -x-2
y=x+2
In order for the other line to be parallel, the slope has to be the same.
(12-6)/(10-4)= 6/6= 1
Both slopes are the same, meaning it is parallel.
The lengths of two sides of the right triangle ABC shown in the illustration given
a= 7cm and b= 24cm
Answer:
25 cm.
Step-by-step explaination:
Given,
Two sides of a triangle:
a = 7cm
b = 24 cm
To find,
Third side:
c = ?
By Pythagorean Theorem;
a² + b² = c²
[where c is the longest side,hypotenuse]
Putting the value of a and b;
we get,
7² + 24² = c²
49 + 576 = c²
625 = c²
25² = c² (square root)
25 = c
c = 25
Therefore, the length of the third side will be equal to 25 cm.
The lengths of two sides of the right triangle ABC shown in the illustration given
a= 7cm and b= 24cm
Given,> a= 7cm
> b= 24cm
To find?Side c (third side)
Solution:-Using Pythagoras theorem,
▶️ a² + b² = c
▶️ 7cm ² + 24cm² = c²
▶️ 49cm + 576cm = c²
▶️ 625cm = c²
▶️ 25² = c² (25×25 = 625)
▶️ c = 25
The value of c is 25 cm.
In the figure, ∆BAT ≅ ∆CAT. Which statement is not true by CPCTC? ∠BTA ≅ ∠CTA ∠BAT ≅ ∠CAT
Answer:
Both are true.
Step-by-step explanation:
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.
Step-by-step explanation:
here is the answer to your question
Find the missing length indicated
Answer:
x = 15
Step-by-step explanation:
x = √{(25-16)×25}
x = √(9×25)
x = √225
x = 15
Answered by GAUTHMATH
Find the lengths of the other two sides of the isosceles right triangle
Answer:
h²=p²+b²
(7√2)²=x²+x²
(49×2)=2x²
2x²=49ײ
x²=49×2/2
x²=49
x=√49=7
x=7
OAmalOHopeO
Plz help me i need this question solution
Answer:
your mom
Step-by-step explanation:
Find the circumference of the circle.
10.1 in
Hint: C = xxd
x= 3.14
A.15.857 in
B.31.714 in
C.63.428 in
D.13.24 in
Step-by-step explanation:
c=3.14×3.14×10.1
=99.58196
Find the value of term a14 in the sequence.
3, 1, –1, –3, –5, . . .
–23
–11
–9
–25
9514 1404 393
Answer:
(a) -23
Step-by-step explanation:
The sequence is arithmetic with first term 3 and common difference -2. Then the general term is ...
an = a1 +d(n -1)
an = 3 -2(n -1)
and the 14th term is ...
a14 = 3 -2(14 -1) = 3 -2(13) = 3 -26
a14 = -23
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
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.
I need to know the answer ASAP thank you
Answer:
Step-by-step explanation:
A. Use the appropriate formula to determine the periodic deposit.
B. How much of the financial goal comes from deposits and how much comes from interest?
Periodic Deposit: $? at the end of each year
Rate: 7% compounded annually
Time: 18 years
Financial Goal: $130,000
The periodic deposit is? $
Answer:
A. Periodic deposit:
The goal is to make $130,000 by depositing a set amount every year.
This set amount is an annuity. The $130,000 is therefore the future value of the annuity after 18 years.
Future value of annuity = Annuity * Future value of annuity factor, 7%, 18 years
130,000 = Annuity * 33.9990
Annuity = 130,000 / 33.9990
= $3,823.64
B. Sources of the financial goal.
Money from deposits = Periodic deposit * no. of years
= 3,823.64 * 18
= $68,825.52
Money from interest:
= Financial goal - Money from deposits
= 130,000 - 68,825.52
= $61,174.48
(B) An airline knows from experience that the distribution of the number of suitcases that get lost each week on a certain route is normal with μ (mean) = 15.5 and σ (standard deviation) = 3.6. What is the probability that during a given week the airline will lose between 11 and 19 suitcases?
Answer:
The correct answer is "0.7289".
Step-by-step explanation:
The given values are:
Mean,
[tex]\mu = 15.5[/tex]
Standard deviation,
[tex]\sigma = 3.6[/tex]
As we know,
⇒ [tex]z = \frac{(x - \mu)}{\sigma}[/tex]
The probability will be:
⇒ [tex]P(11< x< 19) = P(\frac{11-15.5}{3.6} <z<\frac{19-15.5}{3.6})[/tex]
[tex]=P(z< 0.9722)-P(z< -1.25)[/tex]
By using the z table, we get
[tex]=0.8345-0.1056[/tex]
[tex]=0.7289[/tex]
Which of the following fractions is closest to 0? 5/12 , 2/3, 5/6,3/4
Answer:
5/12
Step-by-step explanation:
5/12 , 2/3, 5/6,3/4
Get a common denominator of 12
5/12, 2/3 *4/4, 5/6*2/2, 3/4 *3/3
5/12, 8/12, 10/12, 9/12
The numerator closest to 0 is the fraction closest to 0
5/12
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.)
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:
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?
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
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_____ .
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
