, , , ,
Find the data range by subtracting the minimum data value from the maximum data value. In this case, the data range is .
Find the class width by dividing the data range by the desired number of groups. In this case, .
Round up to the nearest whole number. This will be the size of each group.
Start with and create groups of size .
Determine the class boundaries by subtracting from the lower class limit and by adding to the upper class limit.
Draw a tally mark next to each class for each value that is contained within that class.
Count the tally marks to determine the frequency of each class.