Answer
(a) 7 classes.
(b) Class 1:
lower class limit = 15
upper class limit = 19
Class 2:
lower class limit = 20
upper class limit = 24
Class 3:
lower class limit = 25
upper class limit = 29
Class 4:
lower class limit = 30
upper class limit = 34
Class 5:
lower class limit = 35
upper class limit = 39
Class 6:
lower class limit = 40
upper class limit = 44
Class 7:
lower class limit = 45
upper class limit = 49
(c) Class width = 5
Work Step by Step
(a) Just count the number of classes: 7
(b) For each class, the first number is the lower limit and the second number is the upper limit.
(c) It is the difference between two consecutive lower limits: $20-15=25-20=30-25=35-30=40-35=45-40=5$
