Normal distribution – confidence interval, p-value, margin of error,
Sample question is as under:
Exercise 7-1
Q # 14
Number of jobs. a sociologist found that in a sample of 50 retired men, the average number of jobs they had during their lifetimes was 7.2. the population standard deviation is 2.1.
a. find the best point to estimate of the population men.
b.find the 95 % confidence interval of the mean number of jobs.
c.find the 99% confidence interval of the mean number of jobs.
d. which is smaller? explain why.
Exercise 7-3
Q # 6
Belief in haunted places. a random sample of 205 college students were asked if they believed that places could be haunted, and 65 responded yes. estimate the true proportion of college students who believed in the possibility of haunted places with 99% confidence. according to time magazine,37% of americans believe that places can be haunted.
Exercise 9-4
Q # 4
Undergraduate financial aid. a study is conducted to determine if the percent of women who receive financial aid in undergraduate school is different from the percent of men who receive financial aid in undergraduate school. a random sample of undergraduates revealed these results. at , is there significant evidence to reject the null hypothesis?
|
Women |
Men |
Sample Size |
250 |
300 |
Number receiving aid |
200 |
180 |
more than 20 problems for $18. All problesm are attached in the word file.