Question

Two randomly selected groups of citizens were exposed to different media campaigns that dealt with the image of a political candidate. One week later, the citizen groups were surveyed to see whether they would vote for the candidate. The results were as follows. Is there sufficient evidence to show a difference in the effectiveness of the two image campaigns at the 0.05 level of significance? (Use Conservative - Moderate.)

Exposed to Conservative Image    Exposed to Moderate Image

Number in Sample 100 100

Proportion for the Candidate 0.38    0.50

(a) Find z. (Give your answer correct to two decimal places.)
(ii) Find the p-value. (Give your answer correct to four decimal places.)

(b) State the appropriate conclusion:
Reject the null hypothesis, there is significant evidence to show a difference in effectiveness.
Reject the null hypothesis, there is not significant evidence to show a difference in effectiveness.
Fail to reject the null hypothesis, there is not significant evidence to show a difference in effectiveness.
Fail to reject the null hypothesis, there is significant evidence to show a difference in effectiveness.

Answer 1