00:01
Alright, so in the given question, we have an 80 % confidence interval, which is 154 and 157 .6, right.
00:11
So, this is our lower bound of the confidence interval and this is the upper bound of the confidence interval.
00:17
Now, first part of the question says that what is the mean service time from 505 customers.
00:23
So, the size of the sample here is 505.
00:26
Now, the mean here will be equal to the average of our confidence interval, right.
00:32
So, this will be the upper bound plus the lower bound divided by 2.
00:37
So, this is 157 .6 plus 154 divided by 2.
00:44
So, this is equal to 155 .8, right...