# Statistics Examples

, , , , , , ,
Step 1
The number of classes can be estimated using the rounded output of Sturges' rule, , where is the number of classes and is the number of items in the data set.
Step 2
Select classes for this example.
Step 3
Find the data range by subtracting the minimum data value from the maximum data value. In this case, the data range is .
Step 4
Find the class width by dividing the data range by the desired number of groups. In this case, .
Step 5
Round up to the nearest whole number. This will be the size of each group.
Step 6
Step 7
Determine the class boundaries by subtracting from the lower class limit and by adding to the upper class limit.
Step 8
Draw a tally mark next to each class for each value that is contained within that class.
Step 9
Count the tally marks to determine the frequency of each class.
Step 10
The relative frequency of a data class is the percentage of data elements in that class. The relative frequency can be calculated using the formula , where is the absolute frequency and is the sum of all frequencies.
Step 11
is the sum of all frequencies. In this case, .
Step 12
The relative frequency can be calculated using the formula .
Step 13
Simplify the relative frequency column.
Step 14
Multiply every relative frequency by to get the percentage frequency.
Step 15
Simplify the Percentage column.