Question

(1 point) A recent report for a regional airline reported that the mean number of hours of flying time for its pilots is 56 hours per month. This mean was based on actual flying times for a sample of 51 pilots and the sample standard deviation was 8.5 hours 2. Calculate a 99% confidence interval estimate of the population mean flying time for the pilots. Round your result to 4 decimal places 3. Using the information given, what is the smallest sample size necessary to estimate the mean flying time with a margin of error of 2 hour and 99% confidence? Note: For consistency's sake, round your t' value to 3 decimal places before calculating the necessary sample size. Choosen

Answer 1

The (1-2)/ confidence Junterval for mean . (azo , + Z2 2 / 2 X = sample mean os= Standard deviation ne sample size o= Standard deviation 22 = critical value of z at t Given n=51, 50 = 56, or=8.5 21 - 25% The 99% confidence interval of the flying time for the pilots is population mean ( 56-650)(6.5), 56+6:58) ( 56-30706 56130106] 56 -3.0708 $6+3.0708

The sample size formule ogs where 2 = critical Value 0= 'standard deviation Er error 0978.5. E=2, 20.01 2) 2001 =2.58 (2.58x8.5j2 ne se 230 22 Ano:30