Quizz 1 Solution

5. 73

Feedback: Remember that the mode is the most frequently occurring value in the data set.

6. a

Feedback: The Median is the most stable measurement of central tendency because it is a fixed position in the data set. The mode can be easily moved if one value changes and we discussed how the mean is affected by extreme values.

7. -1 and 1.

8. correlation coefficient

9. descriptive statistics

10. Only b and c.

Feedback: the answer is only b and c because the coefficient of the x term is negative and we're using y = mx + b or y = b + mx as the form of our lines.

11. Qualitative Data

Feedback: The kinds of e-mail messages are qualities. Keep in mind that we can count the number that fall into each category, but the aspect being measured is a quality of the message.

12. take a census.

13. inferential statistics

14. systematic

15. The class width is 5;.

the midpoint of the first class is 137;.

the class boundaries are 134.5-139.5;.

the relative frequencies are (6/44), (4/44), (11/44), (15/44), (8/44);.

as decimals the relative frequencies are approximately 0.1364, 0.0909, 0.2500, 0.3409, 0.1818.

16. 17

Feedback: standard deviation = "square root" of variance = "square root" of 289 = 17.

17. All CIO's from Fortune 1000 companies.

Feedback: The sample of 50 CIO's was drawn from the larger group of 1000 CIO's. Our population is the group that we are trying to represent. The IT developments in 2001 are opinions expressed by each CIO and we can create a response table, but we are sampling CIO's and surveying a subset of this larger group of 1000.

18. The stem and leaf will look like this:

3 | 5 8 7 6 6 5 6.

4 | 4 0 1 1 7 1 3.