chapter 2

Question 1

bar chart

Answer 1

A graphic display device for discrete variables. Categories are represented by bars of equal width, the height of each corresponding to the number (or percentage) of cases in the category.

Question 2

class interval

Answer 2

The categories used in the frequency distributions for interval-ratio variables

Question 3

Cumulative frequency

Answer 3

An optional column in a frequency distribution that displays the number of cases within an interval and all preceding intervals

Question 4

Cumulative percentage

Answer 4

An optional column in a frequency distribution that displays the percentage of cases within an interval and all preceding intervals.

Question 5

Frequency distribution

Answer 5

A table that displays the number of cases in each category of a variable.

Question 6

Frequency polygon

Answer 6

A graphic display device for intervalratio variables. Class intervals are represented by dots placed over the midpoints, the height of each corresponding to the number (or percentage) of cases in the interval. All dots are connected by straight lines. Same as a line chart.

Question 7

Histogram

Answer 7

A graphic display device for interval-ratio variables. Class intervals are represented by contiguous bars of equal width (equal to the class limits), the height of each corresponding to the number (or percentage) of cases in the interval

Question 8

Midpoint.

Answer 8

The point exactly halfway between the upper and lower limits of a class interval.

Question 9

Percentage

Answer 9

The number of cases in a category of a variable divided by the number of cases in all categories of the variable, the entire quantity multiplied by 100.

Question 10

Percent change

Answer 10

A statistic that expresses the magnitude of change in a variable from time 1 to time 2.

Question 11

Pie chart

Answer 11

A graphic display device especially for discrete variables with only a few categories. A circle (the pie) is divided into segments proportional in size to the percentage of cases in each category of the variable.

Question 12

Proportion

Answer 12

The number of cases in one category of a variable divided by the number of cases in all categories of the variable.

Question 13

Rate

Answer 13

The number of actual occurrences of some phenomenon or trait divided by the number of possible occurrences per some unit of time.

Question 14

Ratio

Answer 14

The number of cases in one category divided by the number of cases in some other category.

Question 15

Real class limits

Answer 15

The class intervals of a frequency distribution when stated as continuous categories.

Question 16

Stated class limits

Answer 16

The class intervals of a frequency distribution when stated as discrete categories.

Question 17

midpoints

Answer 17

On occasion, when constructing certain graphs for example, you will need to work with the midpoints of the class intervals. A midpoint is the point exactly halfway between the upper and lower limits of a class interval; it can be found by dividing the sum of the upper and lower limits by 2.