Question

data was collected for 145 randomly selected 10 minute intervals. for each ten - minute interval, the number of people entering the atrium of a large mall were recorded. the data is summarized in the table below.

number of guests	frequency
100 - 119	20
120 - 139	18
140 - 159	10
160 - 179	56

what is the class width for this gfdt?
class width =

Explanation:

Step1: Identify class intervals

The class intervals are 80 - 99, 100 - 119, 120 - 139, 140 - 159, 160 - 179.

Step2: Calculate class width

Take the upper limit of a class and subtract the lower limit of the same class (or the lower limit of the next class minus the lower limit of the current class). For example, using 100 (lower limit of second class) and 80 (lower limit of first class): \( 100 - 80 = 20 \). Or using upper and lower of one class: \( 99 - 80 + 1 = 20 \) (but simpler is difference between lower limits of consecutive classes).

Answer:

20