Answer: (a) 0-2 (b) 3.2
Step-by-step explanation:
modal = the number that appears the most
mean = average
(a) modal class interval: 0 - 2
(b) first, find the mean of each class interval (number of letters delivered):
1, 3.5, 6 and 9
1 x 25 = 25
3.5 x 12 = 42
6 x 8 = 48
9 x 5 =45
25 + 42 + 48 + 45 = 160
number of houses:
25 + 12 + 8 + 5 =50
mean:
160 / 50 = 3.2