Question

A courier company recorded delivery times (in minutes) to deliver parcels to their clients. The sample data is summarized in the cumulative frequency distribution below:

Delivery time (minutes	Cumulative frequency
≤ 10	10
≤ 20	35
≤ 30	58
≤ 40	77
≤ 50	89
≤ 60	100

If the first class in the frequency distribution is 1 – 10, calculate the following:
a) The mean delivery time of parcels to clients by this courier company. [5]

b) The standard deviation of the delivery time of parcels to clients by this courier company.    [10]

c) The median delivery time of parcels to clients by this courier company. [10]

d) The most common courier delivery time? [10]

Answer 1