Question

A political scientist hypothesize that a political ad will increase attitudes about a particular issue. The scientist randomly asks 21 individuals walking by to see the ad and then take a quiz on the issue. The general public that knows little to nothing about the issue, on average, scores 50 on the quiz. The individuals that saw the ad scored an average of 51.8 with a variance of 29.05. What can the political scientist conclude with α = 0.05?

a) What is the appropriate test statistic?
---Select--- na z-test one-sample t-test independent-samples t-test related-samples t-test

b)
Population:
---Select--- the particular issue the political ad individuals walking by general public the ad
Sample:
---Select--- the particular issue the political ad individuals walking by general public the ad

c) Compute the appropriate test statistic(s) to make a decision about H₀.
(Hint: Make sure to write down the null and alternative hypotheses to help solve the problem.)
critical value =  ; test statistic =
Decision:  ---Select--- Reject H0 Fail to reject H0

d) If appropriate, compute the CI. If not appropriate, input "na" for both spaces below.
[  ,  ]

e) Compute the corresponding effect size(s) and indicate magnitude(s).
If not appropriate, input and/or select "na" below.
d =  ;   ---Select--- na trivial effect small effect medium effect large effect
r² =  ;   ---Select--- na trivial effect small effect medium effect large effect

f) Make an interpretation based on the results.

Individuals that watched the political ad scored significantly higher on the quiz than the general public

.Individuals that watched the political ad scored significantly lower on the quiz than the general public.    

Individuals that watched the political ad did not score significantly different on the quiz than the general public.

Answer 1

a) The appropriate test statistic is - z-test

b) Population - general public

Sample - individuals walking by

c)

d)

e) The effect size is

, small effect.

f) Individuals that watched the political ad did not score significantly different on the quiz than the general public.