Answer:
a). 18
b). 26%
c). 39
Explanation:
Given question is incomplete; here is the complete question attached.
a). In this part we have to calculate the number of the people surveyed who make less than 5 calls.
From the given table,
Number of people surveyed who make less than 5 calls Or 1 - 4 calls = 18
b). Total number of people surveyed = 18 + 11 + 5 + 3 + 2 = 39
Number of people surveyed, make at least 9 calls = 5 + 3 + 2 = 10
Percentage of these people =

=

= 25.64%
≈ 26%
c). Total number of people surveyed = 18 + 11 + 5 + 3 + 2 = 39