Question 1108909: A college statistics professor has office hours from 9:00 A.M. to 10:30 A.M. daily.
A sample of waiting times to see the professor (in minutes) is
10, 12, 20, 15, 17, 10, 30, 28, 35, 28, 19, 27, 25, 22, 33, 37, 14, 21, 20, 23
Assuming sigma=7.84, find the 95.44% confidence interval for the population mean.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! A college statistics professor has office hours from 9:00 A.M. to 10:30 A.M. daily.
A sample of waiting times to see the professor (in minutes) is
10, 12, 20, 15, 17, 10, 30, 28, 35, 28, 19, 27, 25, 22, 33, 37, 14, 21, 20, 23
Assuming sigma=7.84, find the 95.44% confidence interval for the population mean.
-----=
Find the mean of those samples (x-bar).
Find the standard deviation:: s
--
If 95.44% is centered on the mean, the tails are each [(1-0.9544)/2]%
= 0.0228
----
Find the z-value border of the right tail:: invNorm(1-0.0228) = 2
-----
Then the margin of error = z*s/sqrt(n) = 2*s/sqrt(20)
------
Ans:: x-bar - ME < u < x-bar + ME
------------
Cheers,
Stan H.
---------
|
|
|
