Airlines must be careful about the total weight of baggage carried by a plane on a commercial flight. Passengers with items exceeding the maximum single-item weight (usually about 70 pounds) must pay a fee (usually about $50.00 per item). Airlines continually monitor the proportion of overweight items in order to evaluate the appropriateness of the overweight fees. English Air charges different amounts for overweight items on flights to the U.S. and Canada than it does on flights within Europe. Recently, a random sample of 256 items checked on English Air flights to the U.S. and Canada contained 37 overweight items, and an independent, random sample of 246 items checked on English Air flights within Europe contained 41 overweight items.

Based on these samples, can we conclude, at the 0.05 level of significance, that there is a difference between the proportion of all items on English Air flights to the U.S. and Canada which are overweight (p1) and the proportion of all items on English Air flights within Europe which are overweight (p2)?

Answers

Answer 1

Answer:

The p-value of the test is 0.4966 > 0.05, which means that we cannot conclude, at the 0.05 level of significance, that there is a difference.

Step-by-step explanation:

Before solving this question, 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.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

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.

To US and Canada:

37 overweight out of 256. So

[tex]p_1 = \frac{37}{256} = 0.1445, s_1 = \sqrt{\frac{0.1445*0.8555}{256}} = 0.022[/tex]

Europe:

41 overweight out of 246. So

[tex]p_2 = \frac{41}{246} = 0.1667, s_2 = \sqrt{\frac{0.1667*0.8333}{246}} = 0.0238[/tex]

Test if there is a difference between the proportion of all items on English Air flights to the U.S. and Canada which are overweight (p1) and the proportion of all items on English Air flights within Europe which are overweight (p2):

At the null hypothesis, we test if there is no difference, that is, if the subtraction of the proportions is 0.

[tex]H_0: p_1 - p_2 = 0[/tex]

At the alternate hypothesis, we test if there is difference, that is, if the subtraction of the null hypothesis is different of 0.

[tex]H_1: p_1 - p_2 \neq 0[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis and s is the standard error.

0 is tested at the null hypothesis:

This means that [tex]\mu = 0[/tex]

From the two samples:

[tex]X = p_1 - p_2 = 0.1445 - 0.1667 = -0.0222[/tex]

[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.022^2 + 0.0238^2} = 0.0324[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{-0.0222 - 0}{0.0324}[/tex]

[tex]z = -0.68[/tex]

P-value of the test:

The p-value of the test is the probability of the sample proportion differing from 0 by at least 0.0222, which is P(|z| > 0.68), which is 2 multiplied by the p-value of z = -0.68.

Looking at the z-table, z = -0.68 has a p-value of 0.2483

0.2483*2 = 0.4966

The p-value of the test is 0.4966 > 0.05, which means that we cannot conclude, at the 0.05 level of significance, that there is a difference.


Related Questions

Quadrilateral is shown in the coordinate plane below.
Draw an image of quadrilateral on the coordinate plane reflected over the y-axis.
​​

Answers

Answer:

A'(6, 2), B'(6, 5), C'(3, 6) and D'(2, 1)

Step-by-step explanation:

Transformation is the movement of a point from its initial location to a new location. Types of transformation are rotation, reflection, translation and dilation.

If a point A(x, y) is reflected over the y axis, the new point is at A'(-x, y).

From the document attached, the vertices of the quadrilateral is at A(-6, 2), B(-6, 5), C(-3, 6) and D(-2, 1). Hence if quadrilateral ABCD is reflected over the y axis, the new point is at A'(6, 2), B'(6, 5), C'(3, 6) and D'(2, 1).

help pleaseee geometryyy

Answers

Step-by-step explanation:

angle ABE=angle EBC

2x+20=4x-620+6=4x-2xx=26/2X=13

stay safe healthy and happy.

Find the volume of x?
I will mark BRAINLIEST

Answers

Answer:

[tex]x=73[/tex]

180-146=34
-39+x=34
34+39=73
x=73
hope this helped!!

For the equation 3(7 + x) = 3x + k, which value of k will create an equation with Infinity many solutions a) 7 b) 21 c) 10 d) 3

Answers

Answer:

21

Step-by-step explanation:

We have to create an identity

3x + 21 = 3x + k

if we substitute k with 21 we have

3x + 21 = 3x + 21

that is an identity so it’s true for every value of x

From her home, Adriana would have to walk due north to get to her friend Gavin's house and due east to get to her friend Zach's house. It is 3 miles from Adriana's house to Zach's house and a straight-line distance of 5 miles from Gavin's house to Zach's house. How far is Adriana's house from Gavin's house?'

Answers

Answer:

4 miles.

Step by step explanation

I REALLY NEED HELP PLS I NEED THIS DONE TODAY!!! JUST LOOK AT THE PICTURE!!!

Answers

Answer:

147 sq meters

Step-by-step explanation:

To find the area of a trapezoid, use the formula ( (a+b)/2 ) x h, where a is base value 1 and b is base value 2. Plugging it all in : ( (4+17)/2 ) = 10.5 x 14 = 147 sq meters.

Answer: the answer is 147 square meters.

Step-by-step explanation:

formula: (a+b)/2 * h

bases are a and b: 4 and 17 meters.

h =14 meters

Plug numbers in (4+7)/2*14

solve and you get 147 square  meters as answer

Find the range of the data.

Answers

Answer:

7.3

Step-by-step explanation:

Biggest value = 8.9

smallest value = 1.6

range = 8.9-1.6 = 7.3

Step-by-step explanation:

range=highest number - lowest number

= 8.9 - 1.6

=7.3

Assume the random variable X is normally distributed with mean μ=50 and standard deviation σ=7. Find the 81st percentile.

Answers

Answer:

[tex]P(81)=56.16[/tex]

Step-by-step explanation:

From the question we are told that:

Mean [tex]\mu=50[/tex]

Standard Deviation [tex]\sigma=7[/tex]

Percentile 81st

Generally Probability of 81st Percentile

 [tex]P(Z<x)=81\%[/tex]

Using Standard normal Table

 [tex]P(Z<0.88)=81\%[/tex]

Therefore the 81st percentile is given as

 [tex]P(81)=z*\sigma *\mu[/tex]

 [tex]P(81)=0.88*7*50[/tex]

 [tex]P(81)=56.16[/tex]

I think it’s 99 but I’m not sure. Can anyone confirm or deny or explain so I can be sure? thank you!

Answers

Answer:

Yeah its B or 99

Step-by-step explanation:

This problem is easy to solve even without a calculator. Simply 10 times 10 would be 100 (since its asking for square root) and the closest number to 100 would be 99 and the square root of 99 is around 9.94.

chipo set out from a on a bearing of 130 to town b ,she then boardef a bus from town b another town c on a bearing of 030 directly east of a. calculate the bearing of town a from her new position​

Answers

Answer:

emm who exactly is chipo bcause i literally have no idea

Calculate the gradient of the line 2y =8x+4

Answers

Answer:

m=4

2y/2=y

8x/2=4x

4/2=2

so

y=4x+4

y= mx+c
y= 2/8x+4
y=4x+2

Instructor Vallejo is trying to figure out the percentage of students that still listen to The Doors. Instructor Vallejo
is pretty out of touch, so he doesn't have a prior percentage of students who listen to The Doors that he can use.
How many students should instructor Vallejo sample if he wants to be within 11% of the actual percentage of
students who listen to The Doors with a 82% confidence level.

Answers

Answer:

N=115

Step-by-step explanation:

n=.25(2.5715/.12)^2 =114.8 so round up to 115. Hope that help you

Anyone help please ):

Answers

Answer:

1.(a) 25.3

(b) 3.49

(c) 14.44

2.(a) 86.64

(b) 59.85

(c) 27.92

3. 5.92

4.(a) 13.96

(b) 43.32

(c) 101.12

5.(a) 59.85

(b) 10.47

(c) 50.6

6. 5.56

A cook needs 42 pieces of tomato for salads The cook has 4 tomatoes He cuts each tomato into 6 pieces

Answers

He only has 24 so 18 left

MEAN: 14,12,17,
ASAP!:((

Answers

Answer:

hello there! I am mizuki, and I'll be helping you with this problem.

Mean is the average in numbers by the way!

Anyways, the answer is about 14.3

or...

14 1/3

Step-by-step explanation:

14 + 12 + 17 = 43

43 ÷ 3 = 14.333333...

1. Given f(x) = x2 – X and g(x) = 3x + 2, find f(g(2))

Answers

Answer:

56

Step-by-step explanation:

g(2) = 3(2) + 2

      = 6 + 2

      = 8

f(8) = 8^2 - 8

     = 64 - 8

     = 56

Funny Question :
What is 1 + 1?

Answers

Answer:

2

Step-by-step explanation add 1+1

2? 1+1 is 2, so your answer would be 2 if it’s a genuine question but if you don’t mind me asking what “funny” about the question? (Not in a rude way just curious!)

Which graph best represents an exponential function?
O A.
O B.
C.
D.

Answers

Answer:

B

Step-by-step explanation:

that's how exponential functions are shaped

A toy manufacturer wants to know how many new toys children buy each year. A sample of 686686 children was taken to study their purchasing habits. Construct the 85%85% confidence interval for the mean number of toys purchased each year if the sample mean was found to be 6.86.8. Assume that the population standard deviation is 2.12.1. Round your answers to one decimal place.

Answers

Answer:

The 85% confidence interval for the mean number of toys purchased each year is (6.7, 6.9).

Step-by-step explanation:

We have that 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 - 0.85}{2} = 0.075[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.075 = 0.925[/tex], so Z = 1.44.

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 = 1.44\frac{2.1}{\sqrt{686}} = 0.1[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 6.8 - 0.1 = 6.7

The upper end of the interval is the sample mean added to M. So it is 6.8 + 0.1 = 6.9

The 85% confidence interval for the mean number of toys purchased each year is (6.7, 6.9).

The rate of change in sales for Garmin from 2008 through 2013 can be modeled by
dS/dT = -0.0972t^2 + 2.136t -11.9
where S is the sales (in billions of dollars) and is the time in years, with t = 8 corresponding to 2008. In 2009, the sales for Garmin were $2.9 billion.
A. Find the model for the sales of Garmin.
B. What were the average sales of Garmin from 2008 through 2013?

Answers

Answer:

a) The model for the sales of Garmin is represented by [tex]S(t) = -\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2} - 11.9\cdot t + 47.112[/tex].

b) The average sales of Garmin from 2008 through 2013 were $ 2.5 billion.

Step-by-step explanation:

a) The model for the sales of Garmin is obtained by integration:

[tex]S(t) = -0.0972\int {t^{2}} \, dt + 2.136\int {t}\,dt -11.9 \int\,dt[/tex]

[tex]S(t) = -\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2} - 11.9\cdot t + C[/tex] (1)

Where [tex]C[/tex] is the integration constant.

If we know that [tex]t = 9[/tex] and [tex]S(t) = 2.9[/tex], then the model for the sales of Garmin is:

[tex]-\frac{81}{2500} \cdot 9^{3} + \frac{267}{250}\cdot 9^{2}-11.9\cdot (9) + C = 2.9[/tex]

[tex]C = 47.112[/tex]

The model for the sales of Garmin is represented by [tex]S(t) = -\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2} - 11.9\cdot t + 47.112[/tex].

b) The average sales of the Garmin from 2008 through 2013 ([tex]\bar{S}[/tex]) is determined by the integral form of the definition of average, this is:

[tex]\bar{S} = \frac{1}{13 - 8} \cdot \int\limits^{13}_{8} {S(t)} \, dt[/tex] (2)

[tex]\bar S = \frac{1}{5}\cdot \int\limits^{13}_{8} {\left[-\frac{81}{2500}\cdot t^{3} + \frac{267}{250}\cdot t^{2}-11.9\cdot t + 47.112 \right]} \, dt[/tex]

[tex]\bar S = \frac{1}{5}\cdot \left[-\frac{81}{10000}\cdot (13^{4}-8^{4}) +\frac{89}{250}\cdot (13^{3}-8^{3}) -\frac{119}{20}\cdot (13^{2}-8^{2}) +47.112\cdot (13-8) \right][/tex][tex]\bar{S} = \frac{1}{5}\cdot (-198.167+599.86-624.75+235.56)[/tex]

[tex]\bar{S} = 2.5[/tex]

The average sales of Garmin from 2008 through 2013 were $ 2.5 billion.

Convert the following angle from degrees to radians. Express your answer in simplest
form.
255°

Answers

Answer:

(17/12)π radians

Step-by-step explanation:

π radians = 180º

255 * (π/180) = (17/12)π

How fast would you reach the water if you jump off a cliff using the formula: h(t)= -16t +8t+ 24?

Answers

Answer:

I don’t know if this is correct

Step-by-step explanation:

Find the area please

Answers

Answer:

[tex]area = \frac{1}{2} \times 11 \times 18 \\ = 99 \: {ft}^{2} [/tex]

In each figure below find m∠1 and m∠2, if a||b. Show your work with statements.

Answers

Answer:

m<1=130°[alternate angle are equal again]

m<1+m<2180°[linear pair]

m<2=180°-130°

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

If you have any questions feel free to ask me^^

Have a nice and great day!

Cayler

#PilipinasAngBayanKo

Answer:nasa picture po

en un rectnagulo de 17 cm de ancho y su diagonal mide 26 cm ¿cuanto mide el rectangulo de largo?

Answers

Answer:

[tex]x=19.67[/tex]cm

Step-by-step explanation:

Por Pitágoras,

[tex]x^{2} = 26^{2} - 17^{2} \\\\x^{2} = 676 - 289\\\\x^{2} =387\\\\x=\sqrt{387} \\\\x=19.67[/tex]

I’m confused. Can someone help? Please and thank you so much!

Answers

Answer:

Root of 65

Step-by-step explanation:

8^2 is equal to 64, so the sqrt of 64 would equal 8 exactly. The question is asking for which of the sqrts would be closest to 8, so sqrt of 65 is the number that is closest to 64, so it is the answer.

Answer:

[tex] \sqrt{65} [/tex]

as

[tex] \sqrt{64} = 8[/tex]

so it's the closest value to 8

and also

[tex] \sqrt{65} = 8.06[/tex]

via calculator

solve each problem part 2a. NO LINKS!!!!​

Answers

Answers:

Problem 14) There are 1093 different ice creams possible.Problem 15) There are 120 ways to pick the reading list.Problem 16)  We have 1365 combinations.Problem 17) There are 315 different combos of cars possible.Problem 18) You can go on 21,700 different combinations of rides.

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

Explanations:

Problem 14

There are n = 10 toppings to choose from.

If you order r = 0 toppings, then there is nCr = 13C0 = 1 way to do this.

Use the combination formula nCr = (n!)/(r!*(n-r)!)

If you order r = 1 topping, then there are 13C1 = 13 ways to do this.

If r = 2, then we have 13C2 = 78 different combos

If r = 3, then 13C3 = 286

If r = 4, then 13C4 = 715

Add up those subtotals: 1+13+78+286+715 = 1093

Note the use of nCr instead of nPr. The order of toppings doesn't matter.

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

Problem 15

Again order doesn't matter. We have n = 10 books to pick from and r = 3 selections to make.

nCr = (n!)/(r!*(n-r)!)

10C3 = (10!)/(3!*(10-3)!)

10C3 = (10*9*8*7!)/(3!*7!)

10C3 = (10*9*8)/(3!)

10C3 = (10*9*8)/(3*2*1)

10C3 = (720)/(6)

10C3 = 120

There are 120 different ways to pick the three books (from a pool of ten).

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

Problem 16

Follow the same steps as problem 15. This time you'll have n = 15 and r = 4. The answer you should get is 1365

Or you could follow these steps below:

We have 15*14*13*12 = 32,760 permutations and 4! = 24 different ways to arrange any group of 4, so we have (32,760)/(24) = 1365 combinations.

nCr = (nPr)/(r!)

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

Problem 17

There are 7C1 = 7 ways to pick the color and 10C2 = 45 ways to pick the two options. Therefore, there are 7*45 = 315 different cars possible.

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

Problem 18

"At least 15" means "15 or more".

If you ride on r = 15 rides, out of n = 20 total, then we have nCr = 20C15 = 15504 different combinations. If you ride on r = 16 rides, out of n = 20 total, then we have nCr = 20C16 = 4845  different combinations. If you ride on r = 17 rides, out of n = 20 total, then we have nCr = 20C17 = 1140  different combinations. If you ride on r = 18 rides, out of n = 20 total, then we have nCr = 20C18 = 190  different combinations. If you ride on r = 19 rides, out of n = 20 total, then we have nCr = 20C19 = 20  different combinations. If you ride on r = 20 rides, out of n = 20 total, then we have nCr = 20C20 = 1  combo only

Add up the subtotals to get

15504+4845+1140+190+20+1 = 21,700

In a clinical test with 2161 subjects, 1214 showed improvement from the treatment. Find the margin of error for the 95% confidence interval used to estimate the population proportion.

Answers

Answer:

The margin of error for the 95% confidence interval used to estimate the population proportion is of 0.0209.

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].

The margin of error is of:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In a clinical test with 2161 subjects, 1214 showed improvement from the treatment.

This means that [tex]n = 2161, \pi = \frac{1214}{2161} = 0.5618[/tex]

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

Margin of error:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]M = 1.96\sqrt{\frac{0.5618*0.4382}{2161}}[/tex]

[tex]M = 0.0209[/tex]

The margin of error for the 95% confidence interval used to estimate the population proportion is of 0.0209.

How to find the value of x round to the nearest tenth for a triangle if one side is 15ft and the other is 13ft

Answers

Answer:

C = 19.9 ft

Step-by-step explanation:

Your question isn't properly constructed. However, I'll attempt in providing a possible way of finding one of the sides of a given triangle.

Generally, the Pythagorean theorem is used to find the side of a triangle when two of its sides are known or provided.

Assuming the following data;

Let the length of sides of the triangle be;

Opposite side = a = 15 ft

Adjacent side = b = 13 ft

Hypotenuse side = c

From Pythagorean theorem;

Mathematically, Pythagorean theorem is given by the formula;

C² = a² + b²

C² = 15² + 13²

C² = 225 + 169

C² = 394

Taking the square root of both sides, we have;

C = √394

C = 19.9 ft

please do both of them THANK YOU

Answers

Answer:

4(3+x)

4x+12

Step-by-step explanation:

Hi there! I am Mizuki, and I'm just answering lol

Anyways, the answer for the first problem is 12 + 4x = 44

The answer for the second problem is 8

Work:

12 + 4x = 44

4x = 32

x = 8

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