# Statistics

posted by .

A student group claims that first-year students at a university must study 2.5 hours (150 minutes) per night during the school week. A skeptic suspects that they study less than that on the average. A class survey finds that the average study time claimed by 269 students is = 144 minutes, with a sample standard deviation of 70.

A) Regard these students as a random sample of all first-year students and suppose we know that the study times follow a Normal distribution. What is the standard error of the sample mean?

B) Consider the hypotheses H0: μ = 150 against Ha: μ < 150. What is the value of the test statistic? Give your answer to two decimal places.

• Statistics -

Z = (144-150/Standard Error (SE) of the mean

SE = SD/sq rt of n-1

I hope this helps.

## Similar Questions

1. ### Statistics

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a standard deviation of 6 hours, what is the required sample size if …
2. ### Statistics

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a standard deviation of 3 hours, what is the required sample size if …
3. ### statistics

A sample of the number of study per week of college students is collected. Some of the sample results of the survey are given in the following table Study Hr 4, 10, 20,24, 34, 36, 42 Z score -2.5,-1.75,-0.5,0, 1.25,1.5,2.25 P. Rank …
4. ### statistic

1. Compute descriptive statistics for liberal art colleges and research universities in the Excel file colleges and universities. Compare the two types of colleges . what can you conclude.?
5. ### Statistics

28. A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spend studying per week. Based on a simple random sample, they surveyed 144 students. The statistics …
6. ### statistics

You and three (3) of your friends were in the same advance placement high school chemistry class in high school. All four (4) of you decided to take the same chemistry class together at the local university along with 21 other students. …
7. ### statistics

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of 6 hours, what is the required sample …
8. ### Statistics

A class survey in a large class for first-year college students asked, "About how many minutes do you study on a typical weeknight?
9. ### statistics

The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 …
10. ### math

A class survey in a large class for first-year college students asked, “About how many minutes do you study on a typical weeknight?

More Similar Questions