The mean number of flight hours for Continental Airline pilots is 49 hours per month. Assume that this mean was based on a sample of 100 Continental pilots and that the sample standard deviation was 11.5 hours. Calculate the margin of error for a 95% confidence interval.

The margin of error for a 95% confidence interval is of 2.18 hours.

Step-by-step explanation:

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 100 - 1 = 99

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 99 degrees of freedom(y-axis) and a confidence level of . So we have T = 1.984

The margin of error is:

In which s is the standard deviation of the sample(square root of the variance) and n is the size of the sample.

In this question:

. So

The margin of error for a 95% confidence interval is of 2.18 hours.

hello from mrbilldoesmath!

answer:

25x^2 + 90x + 84

discussion:

mn(x) = m(n(x)) = m( 5x + 9) =

(5x + 9)^2 + 3 =>

25x^2 + 90x + 9^2 + 3 =

25x^2 + 90x + 84                 (as 9^2 = 9*9 = 81)

which is the second choice

regards,  

mrb

p.s.   i'll be on vacation from friday, dec 22 to jan 2, 2019. have a great new year!

4

step-by-step explanation: