In: Statistics and Probability
An advertising company wants to know whether the size of an advertisement and the color of the advertisement make a difference in the response of magazine readers. A random sample of readers shown ads of 4 different colors and 3 different sizes. Assume that the ratings follow the normal distribution. The rating is shown in the following table:
Size of Ad |
Color of Ad |
|||
Red |
Blue |
Orange |
Green |
|
Small |
4 |
3 |
3 |
8 |
Medium |
3 |
5 |
6 |
7 |
Large |
6 |
7 |
8 |
8 |
a. Using the Excel spreadsheet, construct an ANOVA table.
b. Is there a difference in the effectiveness of an advertisement by color at α =.05? (in your answer, you need to indicate F-static and critical value of F)
c. Is there a difference in the effectiveness of an advertisement by size at α =.05 ? (in your answer, you need to indicate F-static and critical value of F)
Solution:-
a)
b)
State the hypotheses. The first step is to state the null hypothesis and an alternative hypothesis.
Null hypothesis: u1 = u2 = u3 = u4
Alternative hypothesis: At-least one of the u is not equal.
Formulate an analysis plan. For this analysis, the significance level is 0.05.
Analyze sample data.
F statistics is given by:-
F = 3.797
Fcritical = 4.757
Interpret results. Since the F-value (3.797) does not lies in the rejection region, we failed to reject the null hypothesis.
Conclusion:-
Reject H0, There is sufficient evidence for significant differences between the three kinds.
c)
State the hypotheses. The first step is to state the null hypothesis and an alternative hypothesis.
Null hypothesis: u1 = u2 = u3 = u4
Alternative hypothesis: At-least one of the u is not equal.
Formulate an analysis plan. For this analysis, the significance level is 0.05.
Analyze sample data.
F statistics is given by:-
F = 4.932
Fcritical = 5.143
Interpret results. Since the F-value (4.932) does not lies in the rejection region, we failed to reject the null hypothesis.