Question

Lucy Baker is analyzing demographic characteristics of two television programs, Holby City (population 1) and Casualty (population 2). Previous studies indicate no difference in the ages of the two audiences. (The mean age of each audience is the same.). Her staff randomly selected 100 people from each audience, and reported the following: x1 = 43 years and x2 = 45 years. Assume that σ1 = 5 and σ2 = 8. With a two-tail test and α = .05, the critical z values are

Answer 1

Given:

= 43 years and = 45 years. Assume that σ1 = 5 and σ2 = 8. With a two-tail test and α = .05

Hypothesis:

OR There is no difference in the ages of the two audiences.

OR  There is difference in the ages of the two audiences.

Test statistic:

Critical value:

Z_/2 = Z _0.05/2 = 1.96

Conclusion:

|Z| > Z_/2 i.e. 2.12 > 1.96, That is Reject Ho at 5% level of significance

Therefore, there is difference in the ages of the two audiences.