Question

A simple random sample of 5 months of sales data provided the following information: Month: 1 2 3 4 5 Units Sold: 94 105 85 94 92 (a) Develop a point estimate of the population mean number of units sold per month. x = (b) Develop a point estimate of the population standard deviation. If required, round your answer to two decimal places. s =

Answer 1

Answer:

a) x = 94 units/month

b) s = 51.50 units/month

Step-by-step explanation:

The adequate point estimation of the population mean and standard deviation are the sample mean and sample standard deviation.

a) Point estimation of the population (sample mean)

$M=\dfrac{1}{n}\sum_{i=1}^n\,x_i\\\\\\M=\dfrac{1}{5}(94+105+85+94+92)\\\\\\M=\dfrac{470}{5}\\\\\\M=94$

b) Point estimation of the population standard deviation (sample standard deviation)

$s=\dfrac{1}{n-1}\sum_{i=1}^n\,(x_i-M)^2\\\\\\s=\dfrac{1}{4}((94-94)^2+(105-94)^2+(85-94)^2+(94-94)^2+(92-94)^2)\\\\\\s=\dfrac{206}{4}\\\\\\s=51.50$