00:01
Hi, i'm david and i'm here to help you answer your question.
00:03
Now let me pick up your question here.
00:06
In the question here, we are going to discuss about the confidence interval on the mean.
00:13
Now let me remind you that we have the confidence interval for the mill.
00:19
It will be the xb plus or minus the zan4 over 2, time with the sigma over square over square n.
00:26
Now remember that in case we are not given the sigma, we can replace the sigma the n if the n is greater than equal to the 30.
00:35
And in this question here we are given the sample n equals to the 106, so it's greater than 30 already.
00:42
And we are given the symbol mean x bar, so to the 98 point 20.
00:51
And we're given the f to the 0 .62.
00:55
Here we are not given the sigma but we are given the f, but because n greater than 30, so we can replace it.
01:02
We look at the formula we have given the x -par, the s, and the n.
01:06
The order quantity we need to find will be the z and 4 over 2.
01:11
We want to find the 95 % confidence, therefore and 5 % equal to the 2 .5 % which is equal to the 0 .25%, you will look at the zee table, this is equal to the 1 .96...