Bio Statistics
Which one of the following is not a characteristic of a frequency distribution?
It summarizes 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.
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.
A relative frequency distribution shows:
the fraction or percentage of observations in each class interval
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
Which of the following are characteristics of frequency distributions?
Use classes and frequencies to organize data Organize raw data It provides the tally for each class.
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 the cumulative frequency polygon shown, Chart 2-7, about how many observations are there between a value of 200 and 250?
50 Reason: You must subtract the observations for 200 from the observations for 250.
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.
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.
In the histogram shown, Chart 2-4, the minimum profit was at least what amount?
$200
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?"
0.20
Which of the following features is not part of a histogram?
The frequency of occurrence of a nominal variable. 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.
The value shown on the vertical axis of a cumulative frequency polygon for a particular class is found by:
The spread of the data. The concentration of the data. The shape of the distribution. The approximate number of observations.
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
Regarding frequency tables and frequency distributions, which of the following are true?
Both use mutually exclusive classes. Only frequency tables use qualitative data.
Which of the following are characteristics of bar charts?
Plotted rectangles should be the same width. Bar charts are used for qualitative data. There should be gaps between bars.
Which one of the following is true regarding raw data?
Raw data are simply a listing of data before summarizing it.
What is the final step in creating a frequency distribution?
Count 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 is the best definition of "class midpoint"?
Halfway between the lower or upper limits of two consecutive classes.
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 frequency polygon over a histogram?
It shows class midpoints as points on a polygon
Which two of the following practices are commonly used in setting class limits for a frequency distribution?
Rounding the class size up. Placing "excess" interval width equally in the two tails of the distribution.
The number of observations in each class is called the class ______.
frequency
Place the following steps used in constructing a frequency distribution into correct order.
1. Decide on the number of classes 2. Determine class intervals 3. Set individual class limits. 4. Tally the number of observations in each class
In the histogram shown, Chart 2-4, what class had the second highest number of vehicles sold?
1400 to 1800
In the cumulative frequency polygon shown, Chart 2-7, about how many observations are there between a value of 100 and 150?
25 Reason: To get this amount, you must subtract the cumulative frequency for 100 from that for 150.
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
Which of the following can be observed from a histogram? Check all that apply.
The concentration of the data. The shape of the distribution. The spread of the data. The approximate number of observations.
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).
Which of the following are characteristics of frequency tables?
They can be used for qualitative data. No observation can fit into more than one class.
A frequency polygon shows the shape of a distribution and is similar to:
a histogram
