BUSI Test 1

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

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

A histogram

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 are characteristics of raw data?

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

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 2k is greater than the number of observations.

Suppose you are 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 Reason: (70-1)/7=9.86, round up to 10

Given below are the data for blood types: A B B AB O O O B AB B A B 0 O O A O A A 0 A B B 0 AB Which is the frequency for blood type AB?

3 HInt: Just count AB in the sequence

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 2^6 = 64 2^7 = 128

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 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 one of the following is true regarding raw data?

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

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

Both show the number of observations in each class. Only frequency tables use qualitative data.

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.

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 is plotted on the horizontal axis.

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 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.

Which of the following are characteristics of frequency distributions?

It provides the tally for each class. Organize raw data Use classes and frequencies to organize data

Which one of the following is not a characteristic of a frequency distribution? a. It displays the number of observations in each class b. It uses collectively exhaustive classes. c. It uses mutually exclusive classes. d. It summarizes qualitative data.

It summarizes qualitative data

Which of the following can be observed from a histogram? Check all that apply.

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

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

The frequency of occurrence of a nominal variable.