Please be sure to state all answers, commentary and conclusionsusing full senten

Question

Please be sure to state all answers, commentary and conclusionsusing full sentences.

1.     

A company reports that the results of a phone survey indicate80% of Americans prefer their product, with only a 3% margin oferror. Do you trust this report? What problems aren’tincluded in a margin of error? Why are phone surveys still socommon?

2.      This scatterplot of students’ heights looks really strong.What’s wrong with it?

Women

60 61 62 62 63 64 64 65 65 65 65 67 67 67 68 70

Men

63 67 67 67 68 70 70 71 72 72 73 74 74 75 77 79

3.      A student took a conveniencesample of people at the local gym, asking age and weight. Using theregression equation of Weight=-1.16*Age + 214, the studentpredicted that a 10 year old would weigh 202.5 lbs. What’sgoing on here?

Age

22 24 28 30 33 35 39 42 43 49 51 55 56 62 67

Weight

130 165 180 185 250 180 175 170 170 160 160 155 155 138 100

4.      A convenience sample of heightdata was taken, and a two-sample t-test performed, with thefollowing result. Is the difference between men’s andwomen’s heights of practicalsignificance? How can this happen? What can you do to check forthis?

t-Test: Two-Sample Assuming Unequal Variances

Men

Women

Mean

69.58426966

69.08427

Variance

0.722931563

0.722932

Observations

89

89

Hypothesized Mean Difference

0

df

176

t Stat

3.922847422

P(T<=t) one-tail

0.000062649

t Critical one-tail

1.653557436

P(T<=t) two-tail

0.000125298

t Critical two-tail

1.973534347

5.      A fourth-grade teacher takesthe math scores of the 10 tallest and 10 shortest students in theclass, and performs a two-sample t-test on the data. The pvalue issignificant at alpha=0.05, and the teacher concludes that tallerstudents are better at math. What are the problems with thisconclusion?

Women

60 61 62 62 63 64 64 65 65 65 65 67 67 67 68 70

Men

63 67 67 67 68 70 70 71 72 72 73 74 74 75 77 79

Explanation / Answer

2) Since both are independent variables so wecannot find the scatter plot it is non sense 3) From the given data there is some ups anddowns i.e., as the age increases then weight increases and ifthe age decreases it also increases therefore we cannot say it iscorrect 4) WE have to check the p-value 0.000125298,since the p-value is very much less than 0.01, the level ofsignificance so we conclude that the difference betweenmen’s and women’s heights is practicallysignificant 5) What is the conclusion here? If the null hypothesis is likewise i.e., THetaller students does not have the better at mathscores Alternative Hypothesis: THe taller studentshave the better at math scores then this is correct otherwise we cannot saywith this given information

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