Statistics (descriptive)

1. A frequency distribution is a tabular summary of data showing the

• a. fraction of items in several classes.

• b. percentage of items in several classes.

• c. relative percentage of items in several classes.

• d. number of items in several classes.

A frequency distribution is

• a tabular summary of a set of data showing the relative frequency.

• a graphical form of representing data.

• a tabular summary of a set of data showing the frequency of items in each of several nonoverlapping classes.

• a graphical device for presenting categorical data.

The relative frequency of a class is computed by

• dividing the midpoint of the class by the sample size.

• dividing the frequency of the class by the midpoint.

• dividing the sample size by the frequency of the class.

• dividing the frequency of the class by the sample size.

The sum of frequencies for all classes will always equal

• 1.

• the number of elements in a data set.

• the number of classes.

• a value between 0 and 1.

The sum of the relative frequencies for all classes will always equal

• the sample size.

• the number of classes.

• one.

• any value larger than one.

The most common graphical presentation of quantitative data is a

• histogram.

• bar chart.

• stem and leaf display.

• pie chart.

The numbers of hours worked (per week) by 400 statistics students are shown in the table. The cumulative percent frequency for students working less than 20 hours per week is

• 20%

• 25%

• 80%

• 100%

The numbers of hours worked (per week) by 400 statistics students are shown in the table. The class width used in this frequency distribution is

• 4.5

• 9

• 10

• 39

The numbers of hours worked (per week) by 400 statistics students are shown in the table. The midpoint of the last class is

• 35.5

• 34

• 35

• 34.5

Let P be the probability of an event. P = -1 implies

• the event is very unlikely to happen.

• the event is very likely to happen.

• the event will happen surely

• the expression is nonsense.