Question

A simple random sample of  months of sales data provided the following information:

Month	1	2	3	4	5
Units Sold	95	100	87	95	93

a. Develop a point estimate of the population mean number of units sold per month.

b. Develop a point estimate of the population standard deviation (to 2 decimals).

Answer 1

a)

point estimat of population mean = (95 + 100 + 87 + 95+ 93)/5
= 94

b)

Population std.dev = sum of ( sqrt(x - mean)^2/n))
= sqrt[(95 - 94)^2 + (100 - 94)^2+ (87 - 94)^2 + (95 - 94)^2 + (93 - 94)^2)/5]

= 4.20
point estimate of the population standard deviation = 4.20