00:01
So they have a sample of 500 pieces of mail that are going through a reader, and they found that 464 were read properly, scanned properly.
00:13
And you want to write the hypotheses down if they think they want at least 90%, at least 90 % to be read properly.
00:23
And naturally, they'd like to have all of them, but at least 90 % of the zip codes are going to be scanned properly.
00:29
So that would use a proportion test.
00:31
And we would have that it is greater than or equal to 0 .9.
00:36
Alternatively, the proportion is less than 0 .9.
00:40
So those are our hypotheses.
00:43
Now, this is a one proportion z test, and i'm just going to use my software to find what that z value is.
00:52
This is how it's going to be calculated.
00:53
464 divided by 500 minus 0 .9...