stats chapter 2

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

the qualitative class labels.

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

Which of the following are characteristics of frequency distributions?

Use classes and frequencies to organize data. it provides the tally for each class. organize wall data.

which of the following best describes a frequency table?

a grouping of qualitative data into classes showing the number of observations in each class.

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

both show the number of observations in each class.

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

1. decide on the number of classes. 2. determine class interval. 3. set individual class limits. 4. tally the number of observations in each class.

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^k is greater that the number of observations.

a useful way to determine the number of classes (k) in a frequency distribution of n items n. is the "2 to the k rule". which of the following correctly describes this rule?

k is the smallest number such that 2^k>n.

which of the following would useful to represent as a frequency table?

majors of students in a business statistics course. gender of students in a business statistics course. state of residence of students in a business statistics course.

which of the following are characteristics of frequency tables?

no observation can fit into more than one class. they can be use for qualitative data.

which of the following are characteristics of frequency distributions?

organize raw data use classes and frequencies to organize data it provides the tally for each class.

which one of the following is true regarding raw data?

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

In the histogram shown, chart 2-4, the minimum profit was at least what amount?

$200

The number of observations in each class is called the class

Frequency

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 before the class "20 up to 24?"

0.20

Suppose you're trying to summarize a data set with a maximum value of 70 and a minimum value of 1. If you have decided to use seven classes, which one of the following would be a reasonable class interval?

10

In the histogram shown, chart 2-4, what class has the second highest number of vehicles sold?

1400 to 1800

In the histogram shown, chart 2-4, how many vehicles were sold for a profit less than $1400?

23

In the cumulative frequency polygon shown, chart 2-7, about how many observations are there between a value of 100 and 150?

25

Given below are the data for blood types: A B B AB O O O B AB B A B O O O A O A A O A B B O AB Which is the frequency for blood type AB?

3

In the cumulative frequency polygon shown, chart 2-7, about how many observations are there between a value of 200 and 250?

50

A business statistics instructor teaches a class with 83 students. Suppose he would like to create a frequency distribution to summarize their 83 final exam scores. Using the "2 to the K rule," how many classes should used?

7

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

A histogram

Which of the following is an advantage of a cumulative frequency polygon over a histogram or frequency polygon?

It can show the total number of observations less than a particular class' upper limit.

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

In a frequency polygon the points are plotted at the intersection of a class frequencies and the:

Class midpoint

What is the final step in creating a frequency distribution?

Count 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 a class

Which of the following is the best definition of "class midpoint"?

Halfway between the lower or upper limits of two consecutive classes.

Which of the following is an advantage of a frequency polygon over a histogram?

It allows comparing directly two or more frequency distributions.

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.

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. Rounding the class size up.

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 can be observed from a histogram? Check all that apply.

The shape of the distribution. The spread of the data. The approximate number of observations.

which of the following are characteristics of bar charts?

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

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

both use mutually exclusive classes. only frequency tables use qualitative data.

which if 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 relative frequency distribution shows:

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 tree times as big as the accounting slice.

which one of the following is true about pie charts?

the size of a slice should represent the relative frequency or percentage.

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

The frequency of occurrence of a nominal variable.

which one of the following is not a characteristic of a frequency distribution?

it summarizes qualitative data.

which of the following are characteristics of raw data?

raw data can be either qualitative or quantitative. when the data is in its original form it is referred to as raw data.

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

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