# Excel - IF Function Problem - Expert Solution

Question description:
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There is a 62â??% chance that X is above whatâ?? value? if n =25 mean = 100 STD =25
Solved by T. J. in 40 mins
This is the chat thread from the real Excelchat help session. It contains no private user information.
Excelchat Expert 11/09/2018 - 12:02
Hi
Excelchat Expert 11/09/2018 - 12:02
Welcome to Got it Pro
Excelchat Expert 11/09/2018 - 12:03
Please tell a bit more about the requirement so that i can help better
User 11/09/2018 - 12:03
Hi Dianne.
User 11/09/2018 - 12:03
I need to find bar X
Excelchat Expert 11/09/2018 - 12:04
Do you have the graph for normal distribution?
User 11/09/2018 - 12:05
no I do not know how to use it, can you step by step help me set it up on excel
Excelchat Expert 11/09/2018 - 12:08
Do you know this formula Z = (x-mean)/StdDev
User 11/09/2018 - 12:10
yes, but when I uses it on this part of the problem it do not work
Excelchat Expert 11/09/2018 - 12:13
Do you have z table with you?
User 11/09/2018 - 12:14
I do
Excelchat Expert 11/09/2018 - 12:14
so what is the z value when probability is 62%?
Excelchat Expert 11/09/2018 - 12:15
i think it would be nearly 0.4
Excelchat Expert 11/09/2018 - 12:15
what do you see?
User 11/09/2018 - 12:16
I dont know how to read it on the positive or negative side
Excelchat Expert 11/09/2018 - 12:16
there is value for Z and then there is column which says 00
Excelchat Expert 11/09/2018 - 12:16
value in column 00 should be nearly 65%
Excelchat Expert 11/09/2018 - 12:17
and see z value against it
User 11/09/2018 - 12:18
0.31
Excelchat Expert 11/09/2018 - 12:22
-0.31 = (xbar - 100)/(25/sqrt(25))
Excelchat Expert 11/09/2018 - 12:22
Do you see this formula now?
Excelchat Expert 11/09/2018 - 12:22
Just get x bar from this
Excelchat Expert 11/09/2018 - 12:23
once you get the z value just equate it to this formula
Excelchat Expert 11/09/2018 - 12:23
Let me know if you understand
Excelchat Expert 11/09/2018 - 12:23
98.45% probability
Excelchat Expert 11/09/2018 - 12:24
Excelchat Expert 11/09/2018 - 12:24
Let me know if that helps you out
User 11/09/2018 - 12:25
what I do not get is the reading of the chart, why not use 38 since 100-62 = 38
User 11/09/2018 - 12:26
where did the xbar come from - 100 that the number I need to know how to get
Excelchat Expert 11/09/2018 - 12:26
100 is mean
Excelchat Expert 11/09/2018 - 12:26
that is a formula
Excelchat Expert 11/09/2018 - 12:27
Z value = (xbar - mean)/(STD/sqrt(n))
Excelchat Expert 11/09/2018 - 12:27
This is the formula for normal distribution
User 11/09/2018 - 12:28
the xbar what number do you use to get that. I put in and it didnot come out to 98.45
Excelchat Expert 11/09/2018 - 12:28
so if mean is 100 there is 62% probability that X is above 98.45
Excelchat Expert 11/09/2018 - 12:28
I have found out x bar
Excelchat Expert 11/09/2018 - 12:29
-0.31 = (xbar - 100)/(25/sqrt(25))
Excelchat Expert 11/09/2018 - 12:29
This is the equation
Excelchat Expert 11/09/2018 - 12:29
-0.31= (xbar - 100)/(25/5)
Excelchat Expert 11/09/2018 - 12:29
-0.31= (xbar - 100)/(5)
Excelchat Expert 11/09/2018 - 12:30
-0.31*5= (xbar - 100)
Excelchat Expert 11/09/2018 - 12:30
X bar = 100-0.31*5
Excelchat Expert 11/09/2018 - 12:30
Do you get it now?
Excelchat Expert 11/09/2018 - 12:31
Please let me know if this helps you out?
Excelchat Expert 11/09/2018 - 12:31
Are you there?
Excelchat Expert 11/09/2018 - 12:31
Looking forward to good ratings and reviews from you
User 11/09/2018 - 12:31
I'm trying to work it now to see
Excelchat Expert 11/09/2018 - 12:31
User 11/09/2018 - 12:32
It help thank you
Excelchat Expert 11/09/2018 - 12:33
Thanks
Excelchat Expert 11/09/2018 - 12:33
Please do give good rating and reviews when you end the session
Excelchat Expert 11/09/2018 - 12:33
It will really mean a lot
Excelchat Expert 11/09/2018 - 12:33
Have a great day
Excelchat Expert 11/09/2018 - 12:33
Take Caare
Excelchat Expert 11/09/2018 - 12:33
Care*
Excelchat Expert 11/09/2018 - 12:35
Are you there?
Excelchat Expert 11/09/2018 - 12:36
You can end the session to provide your ratings
User 11/09/2018 - 12:36
yes, you help out
Excelchat Expert 11/09/2018 - 12:36
Thanks

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