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 this question we're going to discuss about the complete interval for the mean.
00:11
Let me remind you that the complete interval for the mean.
00:14
It will be the x bar plus and minus z nphal over 2 and then times sigma a.
00:21
This one when the sigma is known.
00:26
And when the signal is unknown, we have to use the x bar plus or minus t n minus 1 degree of freedom and 4 over 2 times s over square of n now in this question we're given the symbol n equal to the 50 the population standard deviation sigma equal to the 6 and then we have the symbol mean equal to 32 now we need to provide the 90 % comfortable b could be 95 and c could be 99 let me remind to you also that for the 9 percent complete interval, the z of the nphal 2, it would equal to the 1 .645.
01:17
For the 95 % common interval, zan4 over 2, it would equal to 1 .96.
01:25
For the 99 % comfortable, zf over 2 equals 2 .575.
01:32
Now because we are given the population standard deviation, therefore we can use the formula for the first one.
01:42
Now let me do the first one here, the 90 % term interval from you.
01:49
It will be the x bar will be the 32 plus or minus 1 .645 and then times the 6 over square with the 50.
02:02
It will compute it.
02:03
We should get the 1 .645 times 6 divided by square root of the 50 get equal to 1 .3958.
02:16
And if we write this down to the node into the interval notation, get equal to the 30 .604 -2...