Question

19. Find the expected count under the null hypothesis. A sociologist was interested in determining if there was a relationship between the age of a young adult (18 to 35 years old) and the type of movie preferred. A random sample of 93 adults revealed the following data. Use a Chi-Square independence test to determine if age and type of movie preferred are independent at the 5% level of significance.

18-23 years old 24-29 years old 3 0-35 years old Totals

Drama 8 15 11 34

Science Fiction 12 10 8 30

Comedy 9 8 12 29

Totals 29 33 31 93

Provided the assumptions of the test are satisfied, find the expected number of 24-29 year-olds who prefer comedies under the null hypothesis.

a) 8

b) 11.56

c) 10.29

d) 7.34

Answer 1

	18-23	24-29	30-35	Total
Drama	8	15	11	34
Science Fiction	12	10	8	30
Comedy	9	88	12	29
Total	29	33	31	93

To calculate the expected value in a chi sqaure under the null hypothesis

Expected value =

is column total

is row total

N is grand total

For 24-29 year-olds who prefer comedies under the null hypothesis.

Expected value =

Expected value = 10.29

c) 10.29