A researcher with the Department of Education followed a cohort of students who graduated from high school in a certainyear, monitoring the progress the students made toward completing abachelor's degree. One aspect of his research was to determine whether students who first attended community college took longer to attain abachelor's degree than those who immediately attended and remained at a4-year institution. The data in the table attached below summarize the results of his study. partsa) throughe) below.

Community College Transfer

No Transfer

n

272

1182

Sample mean time tograduate, in years

5.32

4.25

Sample standard deviation time tograduate, in years

1.167

a) What is the response variable in thisstudy? What is the explanatoryvariable?

A.

The response variable is the use of community college or not. The explanatory variable is the time to graduate.

B.

The response variable is the number of students. The explanatory variable is the time to graduate.

C.

The response variable is the time to graduate. The explanatory variable is the number of students.

D.

The response variable is the time to graduate. The explanatory variable is the use of community college or not.

b) Explain why this study can be analyzed using inference of two sample means. Select all that apply.

A.

The population is given to be normally distributed.

B.

The sample sizes are not more than5% of the population.

C.

The samples are independent.

D.

The samples can be reasonably assumed to be random.

E.

The sample sizes are large(both greater than or equal to30).

c) Does the evidence suggest that community college transfer students take longer to attain abachelor's degree? Use an =0.10 level of significance. Perform a hypothesis test. Determine the null and alternative hypotheses.

A.

H0: communitycollegenotransfer

B.

H0: communitycollege=notransfer, H1: communitycollege

C.

H0: communitycollege>notransfer, H1: communitycollege

D.

H0: communitycollege=notransfer, H1: communitycollege>notransfer

Determine the test statistic.

t=

nothing

(Round to two decimal places asneeded.)

Determine the criticalvalue(s). Select the correct choice below and fill in the answerbox(es) within your choice.

(Round to three decimal places asneeded.)

A.

The critical value is

nothing

.

B.

The lower critical value is

nothing

. The upper critical value is

nothing

.

Should the hypothesis berejected?

Reject

the null hypothesis. The evidence does

suggest that community college transfer students take longer to attain abachelor's degree.

d) Construct a 95% confidence interval for communitycollegenotransfer to approximate the mean additional time it takes to complete abachelor's degree if you begin in community college.

The confidence interval is the range from

to

.

(Round to three decimal places asneeded.)

e) Do the results of partsc) andd) imply that community college causes you to take extra time to earn abachelor's degree?

Yes

No