00:01
Okay, so we're looking at our scenario here of a steel production facility making a type of steel cable.
00:05
So first step for part a, we want our null hypothesis.
00:08
Well, let me write down everything first, i guess.
00:10
We have a sample of 20 cables.
00:14
Standard deviation of that is 0 .04.
00:17
Their sample mean is 1 .98.
00:20
At a confidence level of 0 .05, we want to test whether or not we can accept the given that it's supposed to be 2 kilograms.
00:30
So that means for part a, my null hypothesis is that the mean is 2.
00:35
The alternative hypothesis is that the mean does not equal to 2.
00:40
Okay? so for part b, we want to identify the critical values.
00:49
Since we're doing this, we're going to do a two -tailed test.
00:54
So we're going to take our confidence level and divide it by 2.
00:57
So that's going to be, so basically i'm looking for, whoops, two tail test.
01:04
I want to find the z -score related to the confidence level divided by two...