Good Morning Y'all

Please help,

a random variable r is normally distributed with a mean of 7 and a standard deviation of 2. Find the value of W, so that P(W

Question

Good Morning Y'all

Please help,

a random variable r is normally distributed with a mean of 7 and a standard deviation of 2. Find the value of W, so that P(W<r<10) = 0.8913

Now I did it and got 3.54 but I think this is my r not my w ???

anonymous · Answer

Howdy, Cola =)

anonymous · Answer

hey hey, I hope you can help me with this

anonymous · Answer

So, first of all, a Z-score of a number is pretty simply just describing how many Standard Deviations from the mean that number is.
What is the z-score for 10?

anonymous · Answer

Since the mean is 7 and the SD is 2.

anonymous · Answer

ill let you in on how I got my magical ( probly wrong) anwer 

NormalCDF(-1*10^99,10,7,2) = .9332

.9332 - .8913 = 0.0418

invNorm(0.0418,7,2) = 3.54

anonymous · Answer

I cant just find a z score because it is not on a solid "line" 7 + 2 = 9

anonymous · Answer

Okay, well your method is a bit strange to me, haha, but I've looked over it, and it seems to be valid.

anonymous · Answer

Thank you so very much so my answer is not my r but rather my w right ???

anonymous · Answer

Well, I'm not sure what your complaint is. "I cant just find a z score because it is not on a solid "line" 7 + 2 = 9"

anonymous · Answer

Let me try my own method real quick and see what I get.

anonymous · Answer

|dw:1339687317192:dw|

see there is no way to get a z from just the drawing and the given so we need a calculator :)