Question

5. An important characteristic of histograms, frequency polygons, and stem and leaf displays is a. size. b. total area. c. relative area. d. shape. 6. A frequency distribution of standardized IQ scores for equal numbers of male and female grade school children probably will be a. bimodal. b. normal. c. positively skewed. d. negatively skewed. 7. When constructing a graph, you must first decide on the type of graph. This decision depends on a. the total number of observations. b. whether data are grouped or ungrouped. c. whether data are quantitative or qualitative. d. the impression that you wish to create. 8. Find the median for the following observations: a. 29, 54, 43, 38, 40, 71. b. 21 c. 40.5 d. 41.5 e. 42.5 9. You're told that the shape of the distribution of burning times for light bulbs is balanced (normally distributed), with a mean burning time of about 500 hours. Therefore you can conclude that the median burning time a. equals about 500 hours. b. is more than 500 hours. c. is fewer than 500 hours. d. could be any of the above. 10. When a distribution is skewed, report a. the median. b. both the median and mode. c. both the median and mean. d. the mean. 11. The distribution of annual incomes for U.S. households is positively skewed. If the Census Bureau reports a median annual income of $47,450, this implies that the mean annual income is a. about the same. b. larger. c. smaller. d. either larger or smaller, but it's impossible to decide on the basis of the available information. • NOTE: In Questions 12-13 Identify Which One, If Any, Of The Three Common Averages The Mode, Median Or Mean Probably Serves As The Basis For Each Statement. 12. The average college professor is a white male. a. mode b. median c. mean d. impossible to determine on the basis of available information 13. Among frequency

Answer 1

5. An important characteristic of histograms, frequency polygons, and stem and leaf displays is

d. shape.

6. A frequency distribution of standardized IQ scores for equal numbers of male and female grade school children probably will be a. bimodal.

Since, there will be two modes - one for standardized IQ scores of male and another for standardized IQ scores of female, the frequency distribution will be bimodal.

7. When constructing a graph, you must first decide on the type of graph. This decision depends on

c. whether data are quantitative or qualitative.

We need different type of graphs for quantitative and qualitative data.

8. Find the median for the following observations: a. 29, 54, 43, 38, 40, 71.

d. 41.5

The data in ascending order is 29 38 40 43 54 71 and sample size is 6.

For even sample size n, Median is average of n/2 and n/2+1th element

Median = Average of 3rd and 4th element = (40 + 43)/2 = 41.5

9. You're told that the shape of the distribution of burning times for light bulbs is balanced (normally distributed), with a mean burning time of about 500 hours. Therefore you can conclude that the median burning time

a. equals about 500 hours.

For normal distribution, median is equal to the mean.

10. When a distribution is skewed, report

a. the median.

For skewed distribution, we should use median as measure of center.

11. The distribution of annual incomes for U.S. households is positively skewed. If the Census Bureau reports a median annual income of $47,450, this implies that the mean annual income is

b. larger.

For positively skewed distribution, mean is greater than the median value.

NOTE: In Questions 12-13 Identify Which One, If Any, Of The Three Common Averages The Mode, Median Or Mean Probably Serves As The Basis For Each Statement.

12. The average college professor is a white male.

a. mode

The white male data is a nominal (categorical) data type. The mode is most useful for categorical data measured at the nominal level.