ch 2
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.
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
FREQUENCY DISTRIBUTION
.A grouping of quantitative data into mutually exclusive and collectively exhaustive classes showing the number of observations in each class.
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 would useful to represent as a frequency table?
Gender of students in a business statistics course. Majors of students in a business statistics course. State of residence of students in a business statistics course.
Which of the following is the best definition of "class midpoint"?
Halfway between the lower or upper limits of two consecutive classes.
Which two 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 size up.
Which one of the following is true regarding raw data?
Raw data are simply a listing of data before summarizing it.
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 features is not part of a histogram?
The frequency of occurrence of a nominal variable. 2.Reason: Histograms are used to display properties of quantitative variables. (interval or ratio level)
What information is shown on the horizontal axis of a bar chart?
The qualitative class labels.
A frequency polygon shows the shape of a distribution and is similar to:
a histogram
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 2k >n.
Which of the following best describes a frequency table?
A grouping of qualitative data into classes showing the number of observations in each class.
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. Reason: Unlike a frequency polygon, a cumulative frequency polygon shows class limits.
Which of the following is an advantage of a frequency polygon over a histogram?
It shows class midpoints as points on a polygon.
Which one of the following is not a characteristic of a frequency distribution?
It summarizes qualitative data.
Which of the following are characteristics of frequency distributions?
Organize raw data Use classes and frequencies to organize data
Which of the following can be observed from a histogram? Check all that apply.
The approximate number of observations. The spread of the data. The shape of the distribution. The concentration of the data.
In a frequency polygon the points are plotted at the intersection of the class frequencies and the:
class midpoints
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 are characteristics of frequency tables?
No observation can fit into more than one class. They can be used for qualitative 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).