26. Flight Data: Find the range, variance, and standard deviation. Express answers using appropriate units, such as "minutes."

Question

Refer to Data Set 15 in Appendix B and use the times required to taxi out for takeoff.

Flight 1 1 1 1 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3 3 3 3 19 19 19 19 19 19 19 19 19 19 19 19 21 21 21 21 21 21 21 21 21 21 21 21

Taxi Out 30 19 12 19 18 22 37 13 14 15 31 15 16 14 15 27 19 22 22 23 16 13 16 18 15 12 19 18 21 20 13 15 43 18 17 19 13 20 12 17 35 19 22 43 49 45 13 23

Taxi In 12 13 8 21 17 11 12 12 15 26 9 11 6 7 4 11 10 7 11 10 3 7 7 5 10 10 16 13 9 8 4 3 8 16 9 5 13 4 6 21 29 5 27 9 12 7 36 12

Answer 1

Range = highest value - lowest

Find the mean = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

Standard deviation = square root of variance

I'll let you do the calculations.

Answer 2

The manager of a hotel has stated that the mean guest bill for a weekend is Birr 400 or
less. A member of the hotel’s accounting staff has noticed that the total charges for guest
bills have been increasing in recent months. The accountant will use a sample of weekend
guest bills to test the manager’s claim.