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 11 minutes of the population mean? Assume that the standard deviation of the population of monthly time spent on the internet is 202 min. The minimum sample size required is_______computer users. (Round UP to the nearest whole number.)

Answer 1

1568

Explanation:

The computation of the minimum sample size is shown below:

Given that

Error E = 11

The population standard deviation
`\sigma` =217

Confidence level 1-α = 95%

Now following formula should be used

n > (Zalpha ÷ 2 × sigma ÷ E)^2

As we know that

Zalpha ÷ 2= 1.96

Now the sample size is

n> (1.96 × 202 ÷ 10)^2

= 1568