Question

For the next three (03) items that follow :
The number of telephone calls received in 245 successive one minute intervals at an exchange is given below in the following frequency distribution.

Number of calls	0	1	2	3	4	5	6	7
Frequency	14	21	25	43	51	40	39	12

What is the mean of the distribution?

• A. 3.76
• B. 3.84
• C. 3.96
• D. 4.05

Answer 1

Answer: (A)

3.76

For the given frequency distribution table

$Mean=\frac{\sum \text{number of calls}\times \text{frequency}}{\sum \text{frequency}}$

$Mean=\frac{0\times 14+1\times 21+2\times 25+3\times 43+4\times 51+5\times 40+6\times 39+7\times 12}{245}$

$\therefore$ Mean $=3.76$