Review: Manual Calculation

Question 1

After many yuears of work, a political scientist has noted that political science majors seem more sophisticated, charming, and cosmopolitan than the rest of the student body. A "Sophistication Scale" test has been administered to the entire student body and to a random sample of 100 political science majors, and these results have been obtained:

Student Body: Average=17.3, Standard deviation=7.4

Political science majors: Average=19.2, N=100

Test and find out whether or not political science majors are more sophisticated.


Qestion 2

A random sample of 26 local political science graduates scored an average of 458 on the GRE advanced political science test with a standard deviation of 20. Is this significantly different from the national average of 440?


Question 3

One hundred individuals have been categorized by gender and height, and the reslts are displayed in the table below.

  Male Female Totals
Tall 44 8 52
Short 6 42 48
Totals 50 50 100

a. Calculate an appropriate measure of association. What would you conclude from the statistic?

b. Test the relationship. What would you conclude after testing the relationship?

Question 4

1. Use the following table and calculate an appropriate measure of association and test the relationship.

2. Regression: Calculate the slope and the intercept coefficients.

x y
7 15
6 13
5 3
4 8
6 4

Question 5

Scores on a quiz were normally distributed and had a mean of 10 and a standard deviation of 3. For each score below, find the Z score and the percentage of area above and below the score.


Xi Z score % area above % area below