Question

A survey is being planned to determine the mean amount of time corporation executives watch television. A pilot survey indicated that the mean time per week is 14 hours, with a standard deviation of 2.0 hours. It is desired to estimate the mean viewing time within 30 minutes. The 98% level of confidence is to be used. (Use z Distribution Table.)

How many executives should be surveyed? (Round your z-score to 2 decimal places and round up your final answer to the next whole number.)

Answer 1

we have given = 14 hours, = 2 hours = 120 minutes, Margin of error E = 30 min. and C = 98 %

We have asked to find the sample size for mean.

We know that -

Sample size for mean = [ (Z_0.98 * ) / E ]²

= [ (-2.33 * 120) / 30 ]²

= 86.59

   87

Hence 87 executives should be surveyed

Hope this will help you. Thank you :)