11.
a) Mean is 2 b) Median is 2 c) Sum of square deviations is 56. d) Variance is 2.666 or 2.7 e) Standard deviation is 1.632 or 1.6
12. a) Mean is 1312.4 or 1312 b) Median is 1361 c) Sum of square deviations is 76092.2 d) Variance is 15218.44 e) Standard deviation is 123.363
13.
a) Mean is 3.166 b) Median is 3.25 c) Sum of square deviations is 0.44738 d) Variance is 0.074 e) Standard deviation is 0.272
16.
a) Governor-Mean is 43 and Standard deviation is 5.916
CEO- Mean is 44 and standard deviation is 10.954 b) In order to calculate the mean or average for the governors and CEO’s, I added together all the figures and divided that sum by 4 since there are 4 numbers. Calculate the standard deviation by getting the average of the average (mean) of the numbers. So the average of 43 for the governors is 5.916 and the average of 44 for the CEO’s is 10.954. c) Judging from the results we can see that the CEO’s have bigger desks than the governors. The difference between mean and standard deviation is that mean is the sum of the scores divided by the number of scores and standard deviation is the square root of the average of the squared deviations from the mean.
21
Chapter 3
14.
a) z (340) = (340-300)/20 = 40/20 = 2 b) z(310) = (310-300)/20 = 10/20 = .5 c) z(260) = (260-300)/20 = -40/20 = -2
Raw Scores d) z = 2.4 score = 300 + 20 x 2.4 = 300 +48 = 348 e) z = 1.5 score = 3000 + 20 x 1.5 = 300 + 30 = 330 f) z = 0 , score = 300 g) z = -4.5 , score = 300 + 20 x -4.5 = 300 -90 = 210
15. z(81) = (81-50)/2 = 31/20 = 1.55, z(6.4) = (6.4-0)/5 = 1.28. So, the verbal ability test is higher. You need to figure this out by standardizing both scores by converting them to Z scores.
22.
a) It's a non-random sample because non-random samples are limited because they are not as representative of the population you're studying as random samples are.