Question

A large airport records the percentage of airline flights that land no later than 15 minutes after scheduled arrival. The average of these percentages for 12 months last year was 76.9%. These data become available as soon as feasible. However, the airlines can provide preliminary results by obtaining a sample. The accompanying data contains the sample data indicating the number of minutes after scheduled arrival time that the aircraft arrived. Note that a negative entry indicates the minutes earlier than the scheduled arrival time that the aircraft arrived. Complete parts a through c below. Click the icon to view the table of arrivial times. a. Calculate the proportion of sampled airline flights that landed within 15 minutes of scheduled arrival. (Round to three decimal places as needed.) b. Calculate the probability that a sampled proportion of on-time flights would be within +0.06 of a population proportion equal to 0.769. (Round to four decimal places as needed.) c. If the airlines' goal was to attain the same proportion of on-time arrivals as the previous year, do the preliminary results indicate that they have met this goal? Support your assertions. O A. The sample proportion is contained in the interval found in part b. There is a large chance that a sample proportion O B. The sample proportion is contained in the interval found in part b. There is a small chance that a sample proportion would be contained in this interval given the population proportion is still 0.769 would be contained in this interval given the population proportion is still 0.769. O C. The sample proportion is outside the interval found in part b. There is a small chance that a sample proportion O D. The sample proportion is outside the interval found in part b. There is a large chance that a sample proportion would be outside this interval given the population proportion is still 0.769. would be outside this interval given the population proportion is still 0.769.

Answer 1

Solution a ) Sample size , n=125 x= no. of arrival fall with in £15 is 70 15e arrival time sis) sample proportion. = P = 72 = 70 = 0.56. 125 when P=0.769. = P(Å <pto.o . - P ( Å < P-0.06) P+0.06 P 1 P-0.06 -p ) Spain Spain -0.06 Pl.2 c 0.06 N Jo. 7696-0.769) 10.769 (1-0-169) 125 =pl 2215916) -P(Z < -105916) 0-9442 -0.0557 - 0.8885 option -(A).