Problem 11

  1. (-4.64,-1.36)
  2. No, 5 minutes seems unreasonably high. we are 95% confident that the true mean lies between 4.64 and 1.36 minute faster.

Problem 13

(31.02,40.168) H0: mean=mean2 Ha: mean>mean 2

We are 95% confident that the true mean difference in sugar content of kids cereals is between the interval 31 and 40 g of sugar.

Problem 15

Yes, with a p value of 0.016 is seems as if we should reject the null that the results from the lessons are the same and instead adopt the alternatvive hypthesis that the new tests are actually better.

Problem 17

  1. The normal probabilty plaots of both seemed to have generally stright line trends, meaning that their data is fairly unimodal and syemmetic (nearly normal)
  2. (9.35,10.2)
  3. No, the boxplot looks good.
  4. We want to use different models becuase the combined model has a different standard deviation, and compares their difference directly.

Problem 19

We are 95% confident that the true difference in hitting averages lies between the interval -0.17, 0.88, meaning that we are not certain that one league actually has a higher truer mean of hitting averages.

Problem 21

No, the samples are not independent since they are the same people.

Problem 23

There is a 13% chance that the results we saw were due to random samping variation, meaning that we probabl cannot conclude that this shows us a meaningful difference in type of ad and memory recoloection.

Problem 25

  1. H0:mV - mN = 0 HA:mV - mN violent content and neutral content; viewers of shows with neutral content remember more brand names, on average.

  2. With 95% confidence, the average number of brand names re- membered 24 hours later is between 1.45 and 2.41 higher for viewers of neutral content shows than for viewers of sexual content shows, based on these data.