2.1- Frequency Distributions
correct upper class limits
19, 31, 43, etc
correct lower class limits
8, 20, 32, 44, etc
What is the difference between relative frequency and cumulative frequency?
A frequency histogram will be the same as a relative frequency histogram, except the values on the vertical axis will be different. Relative frequency of a class is the percentage of the data that falls in that class, while cumulative frequency of a class is the sum of the frequencies of that class and all previous classes.
What are some benefits of using graphs of frequency distributions?
By graphing a frequency distribution, it becomes easier to see where the observations are concentrated, making patterns easier to determine.
What are some benefits of representing data sets using frequency distributions?
By organizing data into a frequency distribution, it becomes easier to see where the observations are concentrated, making patterns easier to determine. Organizing the data into a frequency distribution can make patterns within the data more evident.
After constructing a relative frequency distribution summarizing IQ scores of college students, what should be the sum of the relative frequencies?
If percentages are used, the sum should be 100%. If proportions are used, the sum should be 1.
In a frequency distribution, the class width is the distance between the lower and upper limits of a class.
In a frequency distribution, the class width is the distance between the lower or upper limits of CONSECUTIVE classes.
distribution
how data is spread out
frequency distributions
table that shows how many data values fall into categories called classes
midpoint of a class
the sum of the lower and upper limits of the class divided by 2.
Use the given minimum and maximum data entries, and the number of classes, to find the class width, the lower class limits, and the upper class limits. minimum=88, maximum=76, 6 classes
(76-8)/6=12
range
the difference between the maximum and minimum data entries.