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STAT 200 STAT200 WEEK 6 HOMEWORK HYPOTHESIS TESTING WITH TWO SAMPLES

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<strong>STAT</strong> <strong>200</strong> <strong>STAT</strong><strong>200</strong> <strong>WEEK</strong> 6 <strong>HOMEWORK</strong> <strong>HYPOTHESIS</strong> <strong>TESTING</strong><br />

<strong>WITH</strong> <strong>TWO</strong> <strong>SAMPLES</strong><br />

BUY HERE⬊<br />

htp://www.seetutorials.com/stat-<strong>200</strong>-<br />

stat<strong>200</strong>-week-6-homework-hypothesistestng-with-two-samples/<br />

<strong>STAT</strong> <strong>200</strong> Week 6 Homework Hypothesis Testing with Two Samples<br />

Homework Assignment ‐ Hypothesis Testing with Two Samples<br />

Exercises are set up so you can try the problem twice, then the answer will be shown on your third attempt.<br />

If you miss a problem on the exercises and want to improve your score, you can "Try a similar problem", which will<br />

give you a new question of the same type. You can keep on working on versions of a question until you get a perfect<br />

score on the exercises.<br />

#1 Points possible: 2. Total attempts: 3<br />

Test the claim that the proportion of men who own cats is significantly different than the proportion of women who<br />

own cats at the 0.2 significance level.<br />

The null and alternative hypothesis would be:<br />

The test is:<br />

righttailed twotailed lefttailed<br />

Based on a sample of 20 men, 40% owned cats Based on a sample of 80 women, 45% owned cats<br />

The test statistic is: (to 2 decimals)<br />

The pvalue is: (to 2 decimals)<br />

Based on this we:<br />

Reject the null hypothesis<br />

Fail to reject the null hypothesis<br />

Fp> Mp:1H Fμ< Mμ:1H Fμ≠ Mμ:1H Fp< Mp:1H Fμ> Mμ:1H Fp≠ Mp:1H Fp= Mp:0H Fμ= Mμ:0H Fμ= Mμ:0H Fp= Mp:0<br />

H Fμ= Mμ:0H Fp= Mp:0H<br />

#2 Points possible: 2. Total attempts: 3<br />

For each scenario listed on the left, determine whether the scenario represents an Indepenent Samples or Matched<br />

pairs situation by placing the appropriate letter in the box provided.<br />

Comparing pain levels before and after treatment with magnetic therapy<br />

Comparing pretest scores before training to posttest scores<br />

Comparing the number of speeding tickets received by men to the number received by women<br />

Comparing pain levels of a group receiving a placebo to a group receiving a medicine a. Independent Samples<br />

b. Matched Pairs<br />

#3 Points possible: 2. Total attempts: 3<br />

A teacher is experimenting with a new computerbased instruction and conducts a study to test its effectiveness. In<br />

which situation could the teacher use a hypothesis test for matched pairs?<br />

The teacher gives each student in the class a pretest. Then she teaches a lesson using a computer program.<br />

Afterwards, she gives each student a posttest. The teacher wants to see if the difference in scores will show an<br />

improvement.


The teacher randomly divides the class into two groups. One of the groups receives computerbased instruction. The<br />

other group receives traditional instruction without computers. After instruction, each student takes a test and the<br />

teacher wants to compare the performance of the two groups.<br />

The teacher uses a combination of traditional methods and computerbased instruction. She asks students which they<br />

liked better. She wants to determine if the majority prefer the computerbased instruction.<br />

#4 Points possible: 2. Total attempts: 3<br />

5.32 Fuel efficiency of manual and automatic cars, Part I: Each year the US Environmental Protection Agency (EPA)<br />

releases fuel economy data on cars manufactured in that year. Below are summary statistics on fuel efficiency (in<br />

miles/gallon) from random samples of cars with manual and automatic transmissions manufactured in 2012. Do these<br />

data provide strong evidence of a difference between the average fuel efficiency of cars with manual and automatic<br />

transmissions in terms of their average city mileage? Assume that conditions for inference are satisfied.<br />

The hypotheses for this test are:<br />

Ho: μautomatic = μmanual Ha: μautomatic < μmanual<br />

Ho: μautomatic = μmanual Ha: μautomatic > μmanual<br />

Ho: μautomatic = μmanual Ha: μautomatic ≠ μmanual<br />

City MPG, Automatic City MPG, Manual<br />

Mean 16.12 19.85<br />

SD 3.58 4.51<br />

n 26 26<br />

The test statistic is:<br />

The pvalue is:<br />

Interpret the result of the hypothesis test in the context of the problem:<br />

(please round to two decimal places) (please round to four decimal places)<br />

The data provide sufficient evidence that there is a difference between the average fuel efficiency of manual and<br />

automatic cars in terms of their average city mileage<br />

The data do not provide sufficient evidence that there is a difference between the average fuel efficiency of manual<br />

and automatic cars in terms of their average city mileage<br />

The data provide sufficient evidence that there is no difference between the average fuel efficiency of manual and<br />

automatic cars in terms of their average city mileage<br />

#5 Points possible: 2. Total attempts: 3<br />

You wish to test the following claim ( ) at a significance level of . For the context of this problem, where the first data<br />

set represents a pretest and the second data set represents a posttest. (Each row represents the pre and post test<br />

scores for an individual. Be careful when you enter your data and specify what your and are so that the differences<br />

are computed correctly.)<br />

You believe the population of difference scores is normally distributed, but you do not know the standard deviation.<br />

You obtain the following sample of data:<br />

pretest posttest<br />

71.3 67.1<br />

92.6 97.1<br />

76.4 80.5<br />

57.5 58.3<br />

81.8 70.6<br />

27.4 19.2<br />

31.2 31.8<br />

40.3 27.4<br />

65.4 57.7<br />

59.6 52.1<br />

58.2 48.8<br />

56.8 35.1<br />

63.2 68.1<br />

76.4 67.7<br />

65.4 75.3<br />

80.7 74.7


54.6 51.7<br />

53.8 45.4<br />

48.2 35.6<br />

35.5 41.3<br />

What is the test statistic for this sample?<br />

test statistic = (Report answer accurate to 4 decimal places.)<br />

What is the pvalue for this sample?<br />

pvalue = (Report answer accurate to 4 decimal places.)<br />

The pvalue is...<br />

less than (or equal to) greater than<br />

This test statistic leads to a decision to...<br />

<strong>200</strong>.0 = α<br />

tseTerP − tseTtsoP = dμ aH<br />

2μ<br />

1μ<br />

α α<br />

0 ≠ dμ:aH 0 = dμ:oH<br />

reject the null accept the null<br />

fail to reject the null<br />

As such, the final conclusion is that...<br />

There is sufficient evidence to warrant rejection of the claim that the mean difference of posttest from pretest is not<br />

equal to 0.<br />

There is not sufficient evidence to warrant rejection of the claim that the mean difference of posttest from pretest is<br />

not equal to 0.<br />

The sample data support the claim that the mean difference of posttest from pretest is not equal to 0.<br />

There is not sufficient sample evidence to support the claim that the mean difference of posttest from pretest is not<br />

equal to 0.

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