QMB Chapter 2

Suppose a frequency distribution has the following consecutive classes: $20 up to $30 $30 up to $40 $40 up to $50 What is the class midpoint for the first class? Multiple choice question.

$25

Characteristics of bar charts

Plotted rectangles should be the same width, there should be gaps between bars, and used for qualitative data.

Pie chart

A chart that shows the proportioterm-0n or percent that each class represents of the total number of frequencies

Frequency Table

A grouping of qualitative data into mutually exclusive and collectively exhaustive classes showing the number of observations in each class

What is the final step in creating a frequency distribution

count the number of observations in each class

To divide data with a high value of H and a low value of L into k classes, the class interval must be:

At least (h-L)/K

The frequency distribution in the correct order

Decide of the number of classes, determine class interval, set individual class limits, then tally the number of observations in each class

Which of the following practices are commonly used in setting class limits for a frequency distribution?

Placing "excess" interval width equally in the two tails of the distribution, and rounding the class size up

What information is shown on the horizontal axis of a bar chart

The qualitative class labels

the following can be observed from a histogram?

The spread of the data, the shape of the distribution, the approximate number of observations, and the concentration of the data

Characteristics of frequency distributions

Use classes and frequencies to organize data, provides the tally for each class, and organizes raw data

Characteristics of raw data

When the data is in its original form, can be either qualitative or quantitative

The number of observations in each class is called the class _____

frequency

A frequency distribution table shows the number of observations for each class interval of data. How is this data plotted as a frequency polygon?

frequency is plotted on the vertical axis and the class midpoint on the horizontal axis

what type of chart should be shown to show relative class frequency

pie chart

A relative frequency distribution shows

The fraction or percentage of observations in each class interval

A feature of relative frequency distribution

The sum of the relative frequencies must be one

Characteristics of a frequency table

They can be used for qualitative data, no observation can fit into more than one class

Bar chart

A graph that shows qualitative classes on the horizontal axis and the class frequencies on the vertical axis. The class frequencies are proportional to the heights of the bars.

Frequency distribution

A grouping of quantitative date into mutually exclusive and collectively exhaustive classes showing the number of observations in each class.

A frequency polygon shows the shape of a distribution and is similar to:

A histogram

Class midpoint

the value halfway between the lower and upper class limits