1. In words, explain what is measured by each of thefollowing:a. SSb. Variancec. Standard deviation

2. Can SS ever have a value less than zero? Explainyour answer.

6. A population has a mean of m 5 80 and a standarddeviation of s 5 20.a. Would a score of X 5 70 be considered anextreme value (out in the tail) in this sample?b. If the standard deviation were s 5 5, would ascore of X 5 70 be considered an extreme value?

8. Calculate the mean and SS (sum of squared deviations) for each of the following samples. Based onthe value for the mean, you should be able to decidewhich SS formula is better to use.Sample A: 1 4 8 5Sample B: 3 0 9 4

10. For the following sample of n 5 7 scores:8 6 5 2 6 3 5

c. Compute SS, variance, and standard deviationfor the sample. (How well does your estimatecompare with the actual value of s?)

13. A population has a mean of m 5 30 and a standarddeviation of s 5 5.a. If 5 points were added to every score in the population, what would be the new values for the meanand standard deviation?b. If every score in the population were multipliedby 3, what would be the new values for the meanand standard deviation?

22. In an extensive study involving thousands ofBritish children, Arden and Plomin (2006) foundsignificantly higher variance in the intelligencescores for males than for females. Following arehypothetical data, similar to the results obtainedin the study. Note that the scores are not regularIQ scores but have been standardized so thatthe entire sample has a mean of M 5 10 anda standard deviation of s 5 2.a. Calculate the mean and the standard deviation forthe sample of n 5 8 females and for the sample ofn 5 8 males.b. Based on the means and the standard deviations,describe the differences in intelligence scores formales and females.Female9,11,10,13,8,9,11,9 Male 8,10,11,12,6,10,14,9

23. Within a population, the differences that exist fromone person to another are often called diversity.Researchers comparing cognitive skills for younger

adults and older adults, typically find greaterdifferences (greater diversity) in the older population (Morse, 1993). Following are typical datashowing problem-solving scores for two groups ofparticipants.

Older Adults(average age 72)Younger Adults(average age 31)

9 4 7 3 8 7 9 6 7 8

6 2 8 4 5 6 7 6 6 8

7 5 2 6 6 9 7 8 6 9

a. Compute the mean, the variance, and the standarddeviation for each group.

b. Is one group of scores noticeably more variable(more diverse) than the other?

HW #3 – Part 2

Question 1

Find the mode for the following variables

17,1, 5, 5, 17, 17,2, 9, 6, 9,17,17

Question 2

Find the mode for the following variables

2,12, 2, 9, 2,12, 10, 2, 6,12,12

Question 3

Find the median for the following variables

19,3, 8, 14, 19, 19,22, 29, 32, 3,19,19

Question 4

Find the median for the following variables

20,1, 9, 13, 20, 20,23, 30, 35, 37,20

Question 5

Find the mean (average) for the following set of numbers:

x = 3, 6, 14, 3, 5, 9, 10, 16, 11, 9

Be sure to round your answer to the nearest 2 decimal places.

Question 6

Find the mean (average) for the following set of numbers:

x = 11, 22, 12, 24, 12, 6, 10, 9, 9, 7

Be sure to round your answer to the nearest 2 decimal places.

Question 7

Calculate the range for the following variables

2, 8, 10, 9, 4, 6, 9, 14

Question 8

Calculate the range for the following variables

3, 24, 20, 21, 33, 24, 16, 23`

Question 9

Find the population standard deviation for the following values:

Be sure to round your answer to the 2 nearest decimal places.

2, 9, 2, 10, 1

Question 10

Find the population standard deviation for the following values:

Be sure to round your answer to the 2 nearest decimal places.

42, 14, 41, 31, 8