QUESTION 5 What is the appropriate sample size for a time study if a pilot sample of 20 observations has an average of 4 and a standard deviation of 0.35. Assume a 95% confidence (a = 0.05) and that 4% is an acceptable fraction of the mean. (Hint: find first the value of ta/2, df) = QUESTION 5 What is the appropriate sample size for a time study if a pilot sample of 20 observations has an average of 4 and a standard deviation of 0.35. Assume a 95% confidence (a = 0.05) and that 4% is an acceptable fraction of the mean. (Hint: find first the value of ta/2, df) =