Asurvey 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 12 hours, with a standard deviation of 3 hours. it is desired to estimate the mean viewing time within one quarter hour. the 0.95 degree of confidence is to be used. how many executives should be surveyed?

 554

Step-by-step explanation:

Formula we use to find the sample size :

Given : Standard deviation :

Margin of error : E=one quarter hour = 0.25 hour

Two-tailed , Critical value use for 0.95 degree of confidence:

i.e.

Hence, the required sample size = 554

i.e. 554 executives should be surveyed.

i believe your answer is 99.7% of 7-year-old children are between 46.6 inches and 49.5 inches tall.