10. Based on a random sample of 13 tire changes, the mean time to change a tire on a Boeing 777 has a mean of 59.5 minutes with a standard deviation of 8.4 minutes. For 10 tire changes on a Boeing 787 the mean time was 64.3 minutes with a standard deviation of 12.4 minutes. To test for equal variances in a two-tailed test at alpha =.10, the critical values are: Select one: 3.73 and. 228 2.51 and 3.67 3.07 and. 398 3.07 and. 357

Answer: 3.07 and 0.357

Step-by-step explanation:

To solve the problems above, we use the F - distribution or statistic to test the equality of variance in a two tailed test.

We can employ the excel function:

F. INV. RT (alpha, deg_of _freedom1, deg_of_freedom2) to get the right tail and

F. INV (alpha, deg_of _freedom1, deg_of_freedom2)

alpha = 0.1

For a two tailed test;

Alpha = 0.1 : 2 = 0.05

Deg_of freedom1 = (number of observation1 - 1)

Deg_of freedom1 = 13 - 1 = 12

Deg_of freedom2 = (number of observation2 - 1)

Deg_of freedom2 = 10 - 1 = 9

Right tail:

F. INV. RT (0.05,12,9) = 3.07

F. INV (0.05,12,9) = 0.357