Question

Use the following for the next 4 questions: A recent national survey found that high school students watched an average of 6.8 DVDs per month with a population standard deviation of 2.5 hours. The distribution of times follows the normal distribution. A random sample of 36 college students revealed that the mean number of DVDs watched last month was 6.1. At the 0.05 significance level, can we conclude that college students watch fewer DVD's a month than high school students (average of 6.8 DVDs per month)? H subscript 0 colon space mu greater or equal than 6.8 H subscript 1 colon space mu less than space 6.8

a) What kind of test is this?

		One-tail (right tail)
		Two-tail
		One-tail (left tail)

B) What is the Critical Value?

C) c) Calculate the test statistic. Round to two decimal places.

d) What is your decision regarding the null hypothesis?

Reject or Do not Reject?

e) What is your conclusion?

		College students watch fewer DVDs than high school students.
		College students do not watch fewer DVDs than high school students.

Answer 1

Ho :  
Ha :  
a) This is a One-tail (left tail) test.

b) Level of significance(l.o.s.) :   = 0.05
Critical value = Z () = Z (0.05) = -1.6449 (from Z tables)

c) Calculations :   = 6.1,   = 2.5 & n = 36

Z cal =   =   = -1.68

d) Since Z cal < Z tab, we reject Ho at 5% l.o.s.

e) Thus, we conclude that college students watch fewer DVDs than high school students.

Hope this answers your query!