Question

A doctor wanted to know if watching a short, 15-minute, anti-smoking video would change people’s attitudes about smoking. Participants were given a survey to determine their attitude toward smoking before and after watching the anti-smoking video. The doctor hypothesized that the participants would have a lower score (have a more negative attitude) after watching the video than before. Answer the questions based on the information given below the questions. Use alpha = .01.

Mean : Before watching = 5.548 After watching = 2.912

Variance : Before watching = 1.212546184 After Watching = 2.193028112

Observations : Before Watching = 250 After Watching = 250

df : 249

t stat : before watching = 21.68455

a. What type of test is this? Be specific.

b. Write the null hypothesis.

c. Write the alternative hypothesis.

d. How many participants were in the sample?

e. What is the value of the test statistic?

f. What is the critical value with alpha = .01? (need the table in the book)

g. Is the result statistically significant?

h. Write the result in correct APA statistical notation

. i. Summarize the results in one sentence or two sentences.

Answer 1

a. What type of test is this? Be specific.

paired t test as before and after watching video same Participants are measured score

b. Write the null hypothesis.

participants would have a same score (have a more negative attitude) after watching the video than before.

c. Write the alternative hypothesis.

participants would have a lower score (have a more negative attitude) after watching the video than before.

d. How many participants were in the sample?

total participants=df+1=249+1=250

e. What is the value of the test statistic?

t stat=21.68455

f. What is the critical value with alpha = .01? (need the table in the book)

=T.INV(0.99,249)

=2.341416765

g. Is the result statistically significant?

test statistic>t critical

21.68455>2.341416765

result is statistically significant

. Write the result in correct APA statistical notation

There is suffcient statistical evidence at 5% level of significance to conclude that the participants would have a lower score (have a more negative attitude) after watching the video than before.