Use the same formula you have to find the z-score
I don't know if you use tables from the back of a textbook, or some webpage like David Lane's fabulous page
http://davidmlane.com/hyperstat/z_table.html
suppose that the percentage of Alice getting a mark of 75 or less is .62
If the SD is 6 marks what is the mean of the class.
(75 - mean)/6 = .62
75 - mean = 3.72
mean = 75 - 3.72 = appr 71.3
How do I find the value of the mean, when I am only given the std dev of a normal distribution and a percentage of values greater than another value.
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