Chapter 2 Practice

In the histogram shown, the minimum profit was at least what amount? Profit $: (horizontal line) 200-3400

$200

Given below are limits for two consecutive classes for a frequency distribution that summarizes student grade point averages. Which set of limits is is best?

3.000 up to 3.250 3.250 up to 3.500

Which of the following is true regarding raw data?

Raw data are simply a listing of data before summarizing it.

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

at least (H-L)/k

Which of the following features is an advantage that the frequency polygon has over the histogram?

it can directly compare two or more frequency distributions

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

Class frequency

Which of the following would be use of a frequency table?

- Gender of students in a business statistics course.- State of residence of students in a business statistics course.- Majors of students in a business statistics course.

Which of the following are true regarding the class midpoint?

-It is halfway between the upper limits of two consecutive classes -it is halfway between the lower limits of two consecutive classes -it best represents the value in a class

In the cumulative frequency polygon shown, about how many observations are there between a value of 100 and 150? Selling price 100- Frequency 35 Selling price 150- Frequency 50

25 35-50=25 To get this amount, you must subtract the cumulative frequency for 100 from that for 150.

Regarding frequency tables and frequency distributions, which one of the following is true?

-both show the number of observations in each class

The value shown on the vertical axis of a cumulative frequency polygon for a particular class is found by:

-counting the number of observations less than the upper limit of the class

Which of the following graphs are used to summarize quantitative data?

-histogram -frequency polygon

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

-placing "excess" interval width equally in the two tails of the distribution. -rounding the class interval up.

Which of the following are characteristics of bar charts?

-plotted rectangles should be the same width -there should be gaps between bars -bar charts are used for qualitative data

which of the follow can be observed from a histogram?

-the approximate number of observations -the spread of the data -the concentration of the data -the shape of the distribution

Suppose that the miles per gallon for 80 cars is summarized in a frequency distribution. Below is a part of the distribution. What would the relative frequency be for the class "20 up to 24?" MPG -16 up to 20 -20 up to 24 Frequency -10 -16

0.20 16/80=0.20

Which of the following features is not part of a histogram?

The frequency of occurrence of a nominal variable.

Which of the following is not a useful practice in setting individual class limits for a frequency distribution?

Excluding outliers that cause the interval to be too wide.

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 is plotted on the horizontal axis.

in using the "2 to the K rule" to determine the number of classes for a frequency distribution, what is the meaning of the variable k?

K is the smallest number of classes such that 2* is greater than the number of observations.

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

The qualitative class labels.

Which of the following operations is true regarding relative frequency distributions?

The relative frequency is found by dividing the class frequencies by the total number of observations.

which of the following is a feature of relative frequency distribution?

The sum of the relative frequencies must be (assuming no rounding errors).

Suppose a cumulative relative frequency distribution is used to summarize n observations. The cumulative relative frequency for the last class will always be

equal to one

A cumulative frequency distribution

shows the proportions of observations less than each class upper limit.

Relative frequencies are:

the fraction or percentage of observations in each class interval.

A business statistics course has 2 accounting majors, 4 finance majors, 6 marketing majors, and 8 insurance majors. Which one of the following is true if a pie chart was constructed to depict majors of students?

the marketing slice would be three times as big as the accounting slice.

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?

$25 (20+30)/2=25

Place the following steps used in constructing a frequency distribution into correct order.

1. Decide on the number of classes 2. Determine class width. 3. Set individual class limits. 4. Tally the number of observations in each class.