Question 9 (1 point)

The American Airlines flights would like to study the departure delay time. They would like to test the claim that the mean departure delay time for all flights from New York to Los Angeles is less than 12 min. They recorded 64 different departure delay times and found the mean is 10 min and the standard deviation is 30 min. Use a 0.01 significance level to test the claim.

3. what is the degree of freedom?

Question 9 options:

a)

30

b)

64

c)

63

d)

8