An employment agency wants to see which of three types of ad

An employment agency wants to see which of three types of ads in the help-wanted section of local newspapers is the most effective. Three types of ads (big headlines, straightforward, and bold print) were randomly alternated over a period of weeks, and the number of people responding to the ads was noted each week.

Do these data support the null hypothesis that there is no difference in the effectiveness of the ads, as measured by the mean number responding, at the .01 level of significance?

(a) Find the test statistic. (Give your answer correct to two decimal places.)


(b) Find the critical value. (Give your answer correct to two decimal places.)

(c) State the appropriate conclusion.

Reject the null hypothesis, there is not significant evidence of a difference in effectiveness of the ads.

Reject the null hypothesis, there is significant evidence of a difference in effectiveness of the ads.    

Fail to reject the null hypothesis, there is significant evidence of a difference in effectiveness of the ads.

Fail to reject the null hypothesis, there is not significant evidence of a difference in effectiveness of the ads.

Solution

H0: there is no difference in the effectiveness of the ads,

Ha: There is difference

Alpha = 0.01

chi-square = 32.4
degrees of freedom = 10
probability = 0.000

Conclusion: Reject the null hypothesis, there is significant evidence of a difference in effectiveness of the ads.