00:01
Hi, i'm david and i'm here to have you and send your question.
00:03
Now let me bring up your question here.
00:05
In the question here we are going to discuss about the confidence interval for the mean.
00:10
The formula will be the x bar plus and minus the critical value z and far over 2 time with the sigma the value square n.
00:18
And this quantity here will become the merging of the error denoted by the e.
00:23
In this question here we're given the same size n equal to the 100.
00:30
120 and then we have the sample mean x bar equal to the 49 ,560 and we're given the sigma equal to the 920 and in the first question one asked to find the 98 % confidence interval look at the formula we have to find the z unf a virtue first now at the 98 % confidence and file equal to the 2 % devalued 2 % which is equal to the 0 .01.
01:05
If we look at the c table, this value equal to the 2 .33.
01:09
Therefore, we have the 98 % confidence interval for the mean.
01:14
We have the x bar equal to the 49560 plus a minus 2.
01:21
23, time with the sigma will be the 920, the 1b square root of the 120.
01:28
Now if we compute the quantity on the right, we have the number, the 3 .33 times 920, the 5x square root of 120 equals to the 195 .68...