# The Mean of X Based on Standard Deviation

If X is a normal random variable with standard deviation 4.00, and if the probability that X is more than 5.52 is .305, than what is the mean of X?

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#### Solution Preview

Denote by mu the mean of X. Given

P(X>5.52)=0.305

i.e.,

P((X-mu)/4> ...

#### Solution Summary

This solution computes the mean of variable X.

$2.19