Question 1

In a classic study in the are of problem solving, Katona (1940) compared the effectiveness of two methods of instruction. One group of participants was shown the exact, step-by-step procedure for solving a problem and was required to memorize the solution. Participants in a second group were encouraged to study the problem and find the solution of their own. They were given helpful hints and clues, but the exact solution was never explained. The study included the problem in the following figure showing a pattern of five squares made of matchsticks. The problem is to change the pattern into exactly four squares by moving only thee matches. (All matches must be used, non can be removed, and all the squares must be the same size.) After 3 weeks, both groups returned to be tested again. The two groups did equally well on the matchstick problem they had learned earlier. But when they were given new problems (similar to the matchstick problem), the memorization group had much lower scores than the group who explored and found the solution on their own. The following data demonstrate this result.

Memorization of the Solution

Find a Solution on Your Own

n=8

n=8

M=10.50

M=6.16

SS=108

SS=116

a. Is there a significant difference in performance on new problems for these two groups? Use a two tailed test with ?=.05.

b. Construct a 90% confidence interval to estimate the size of the mean difference.

c.Compute the estimated value for Cohen's d to measure the size of the effect

Question 2

Hypothesis Testing- 2 samples

One of the questions in a study of marital satisfaction of dual-career couples was to rate the statement, "I'm pleased with the way we divide the responsibilities for childcare." The ratings went from 1 (strongly agree) to 5 (strongly disagree). The table below contains ten of the paired responses for husbands and wives. Conduct a hypothesis test at the 5% level to see if the mean difference in the husband's versus the wife's satisfaction level is negative (meaning that, within the partnership, the husband is happier than the wife).

Wife's score

3

2

2

3

4

2

1

1

2

4

Husband's score

2

2

1

3

2

1

1

1

2

4

NOTE: If you are using a Student'st-distribution for the problem, including for paired data, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.)

Part 1) State the distribution to use for the test. (Enter your answer in the formzort_dfwheredfis the degrees of freedom.)

Part 2) What is the test statistic? (If using thezdistribution round your answer to two decimal places, and if using thetdistribution round your answer to three decimal places.)

z or t=_____

Part 3) What is thep-value? (Round your answer to four decimal places.)

Question 3

The percentage of adult users of the Internet who use Facebook has increased over time

(Pew Research Internet Project, 2013). Of adult Internet users age 18-49, 81% use Facebook.

Of adult Internet users age 50 and older, 54% use Facebook. Assume that 52% of

adult Internet users are age 18-49.

a. What is the probability that a randomly selected adult user of the Internet is age 50

or older?

b. Given that an adult Internet user uses Facebook, what is the probability that he/she is

age 18-49?

Question 4

The percentage of adult users of the Internet who use Facebook has increased over time

(Pew Research Internet Project, 2013). Of adult Internet users age 18-49, 81% use Facebook.

Of adult Internet users age 50 and older, 54% use Facebook. Assume that 52% of

adult Internet users are age 18-49.

a. What is the probability that a randomly selected adult user of the Internet is age 50

or older?

b. Given that an adult Internet user uses Facebook, what is the probability that he/she is

age 18-49?

Question 5

Would you expect the F-ratio of an independent-samples ANOVA using the same data to be the same, higher than, or lower than the F-ratio of a repeated measures ANOVA?