Question

A chocolate distributor wants to estimate the mean amount of chocolate people will buy in the month of December at a 99% confidence level. If the distributor knows that the population standard deviation is 50 kgs and the store wants to be within 20 kgs of the population mean, what is the minimum sample size the store should choose?

a. 25

b. 42

c. 107

d. 166

Answer 1

Given that, population standard deviation = 50 kgs and

margin of error (E) = 20 kgs

A 99% confidence level has significance level of 0.01 and critical value is,

We want to find, the sample size (n),

=> n ≈ 42 (rounded to next whole number)

Therefore, minimum sample size the store should choose is 42

Answer: b) 42