00:01
So in this question, you are giving sample number to be 30 .8, standardization to be 30 .8.
00:08
So for battery, we are giving sample site to be 100.
00:13
Confidence level to be 95%.
00:15
So we get alpha to be 190, 0 .95, which is 0 .05.
00:22
So alpha on 2 will give us 0 .025.
00:27
So our z alpha on 2 will be 1 .9.
00:32
So we can find our 95 % confidence interval to be x bar plus or minus.
00:38
Set alpha on two times signal on the root of n.
00:42
So we get 33 .8 plus or minus 1 .96 times 3 .8 over the root of 100.
00:52
So this gives us 33 .8 plus 1 minus 0 .75.
01:00
So we get a confidence interval of 30 .5.
01:03
53 .055 and 34 .545.
01:13
For part b, we have n20, 400.
01:20
The same confidence level, so our z alpha 1 2 is 1 .96...