Chapter 2

Question 0

Define class

Answer 0

Intervals of data entries with a count of the number of entries in each class

Question 1

Define frequency distribution

Answer 1

A table that shows classes or intervals of data entries with a count of the number of entries in each class.

Question 2

Define frequency

Answer 2

The frequency f of a class is the number of data entries in the class

Question 3

Define class width

Answer 3

The distance between lower or upper limits of consecutive classes

Question 4

Define class limit

Answer 4

Lower class limit is the least number that can belong to the class. The upper class limit is the greatest number that can belong to the class

Question 5

Define midpoint

Answer 5

The midpoint is the sum of the lower and upper limits of the class divided by two

Question 6

Define relative frequency

Answer 6

The portion or percentage of the days that falls in that class. Class frequency divided by sample size

Question 7

Define cumulative frequency

Answer 7

The sum of the frequencies of that class and all previous classes

Question 8

Define class boundaries

Answer 8

The numbers that separate classes without forming gaps between them

Question 9

Define histogram

Answer 9

A bar graph that represents the frequency distribution of a data set

Question 10

What symbol does f represent

Answer 10

Frequency

Question 11

What symbol does n represent

Answer 11

Sample size

Question 12

Define measure of central tendency

Answer 12

A value that represents a typical, or central, entry of a data set. Mean, median, and mode

Question 13

Define mean

Answer 13

The sum of the data entries divided by the number of entries. Symbol looks like a fancy u

Question 14

Define median

Answer 14

The value that lies in the middle of the data when the data set is ordered

Question 15

Define mode

Answer 15

The data entry that occurs with the great frequency

Question 16

Define outlier

Answer 16

A data entry that is far removed from other entries in the data set

Question 17

Define symmetric distribution

Answer 17

A vertical line can be drawn through the middle of the graph of the distribution and the resulting halves are approximately mirror images

Question 18

Define uniform distribution

Answer 18

All entries or classes in the distribution have equal or approximately equal frequencies. Also symmetric

Question 19

Define skewed left distribution

Answer 19

Negatively skewed distributor if it’s tail extends to the left

Question 20

Define skewed right distribution

Answer 20

Positively skewed if it’s tail extends to the right

Question 21

Define weighted mean

Answer 21

The mean of a data set whose entries have varying weights. Calculated by sum of entry times weight divided by sum of all weights

Question 22

What is graphed on a pie chart

Answer 22

Pie charts present qualitative data graphically as percents of a whole. The area of each sector is proportional to the frequency of each category

Question 23

What is unique about a Pareto chart?

Answer 23

Graphs qualitative data in a vertical bar graph in which the height of each bar represents frequency or relative frequency. Bars are positioned in order of decreasing heights

Question 24

What is meant by paired data sets

Answer 24

When each entry in one data set corresponds to one entry in a second data set. Graphed as scatter plots

Question 25

What is a time series chart

Answer 25

A data set that is composed of quantitative entries taken at regular intervals over a period of time and graphed. Different from a scatter plot because data points are connected by a line