Question

In order to estimate the mean amount of time computer users spend on the internet each month, how many computer users must be surveyed in order to be 95% confident that your sample mean is within 12 minutes of the population mean? Assume that the standard deviation of the population of monthly time spent on the internet is 218 min. The minimum sample size required is_______computer users. (Round UP to the nearest whole number.)

Answer 1

The minimum sample size 'n' = 1267.78

Explanation:

Step:-1

Given that the sample mean is within 12 minutes

Given that the standard deviation of the Population(σ) = 218

Level of significance = 0.05

Critical value (Z₀.₀₅) = 1.96

Step(ii):-

The estimated error is defined by

`E = (Z_(0.05)S.D )/(√(n) )`

`12 = (1.96 X 218)/(√(n) )`

`√(n) = (1.96 X 218)/(12)`

√n = 35.606

squaring on both sides, we get

n = 1267.78

Final answer:-

The minimum sample size 'n' = 1267.78