In a normal distribution 31% of the items are under 45 and 8% are over 64. Find the mean and S.D. of the distribution.
I need some help on the above number. Thanx.
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Find the value of such that .
From it follows that .
Substitute your value of to get equation (1) with the unknowns and .
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Find the value of such that .
From it follows that .
Substitute your value of to get equation (2) with the unknowns and .
Solve equations (1) and (2) simultaneously.