In: Statistics and Probability
Will your flight get you to your destination on time? To the right are a histogram and summary statistics for the percentage of delayed arrivals each month from 2001 thru 2006. Consider these data to be a representative sample of all months. There is no evidence of a time trend. (The correlation of Flights Delayed % with time is r=0.0160.016.) n= 72 x= 24.5556 s= 3.34564 |
a) Check the assumptions and conditions for inference about the mean. Select all that apply.
A. All of the assumptions and conditions for inference about the mean are met.
B. The 10% condition is not met.
C. The randomization condition is not met and the sample is not suitably representative.
D. The independence assumption is not met.
E. The nearly normal condition is not met.
b) Find a 99% confidence interval for the true percentage of flights that arrive late.
___ < (Delayed Flight)< ___ (Round to two decimal places as needed.)
c) Interpret this interval for a traveler planning to fly. Choose the correct answer below.
A. 99% of all months have delayed flights rates within the interval.
B. A randomly selected month has a 99% chance of having a delayed flight percentage within the interval.
C. We can be 99% confident that the interval contains the true mean monthly percentage of delayed flights.
D. There is a 99% chance that the true mean monthly percentage of delayed flights is within the interval.