Was doing an essay for another class only have an hour left thought i'd try posting
3. On a university entrance examination, student test scores are known to be normally
distributed with a mean of 500 points and a standard deviation of 75 points. One
high school principal claims that her school’s graduates scored higher than the
population mean. To support her claim, she asked the examiners to randomly select
49 of her school’s students who wrote the examination. She found that the mean
score for this sample was 520. Assuming the population standard deviation applies
to her students, does this result support her claim at the 5% level of significance?
What is the p-value in this case?
4. The average weight of a box of cereal manufactured at Quaker Oats in
Peterborough is supposed to be at least 18 ounces. A sample of 18 packages
showed a mean weight of 17.78 ounces with a sample standard deviation of 0.41
ounces. At the 5 percent level of significance, test the hypothesis that the mean
weight of these boxes is less than 18 ounces against the null hypothesis that the
mean weight is at least 18 ounces. Assume that the population is normally
distributed.
5. Melvin claims that his average golf score is no more than 75. Melvin lies a lot so
you observe his game for a random sample of 9 rounds and find that the sample
mean is 79 strokes with a sample standard deviation of 4 strokes. At the .05 level of
significance, should you reject Melvin’s claim? Assume his game scores are
normally distributed.
6. Acme Advertising was awarded a contract by a city government to communicate the
need for recycling. Before their advertising campaign, survey results indicated that
36% of the city’s residents believed in recycling. After the campaign, a follow-up
survey of 50 residents found that 24 of them believed in recycling. At the 1 percent
level of significance, test the hypothesis that the campaign has had an effect on
attitudes towards recycling against the null hypothesis that the percentage of city
residents believing in recycling has not increased.