TITLE: Normal distribution, propability of cost.
QUESTION [0 upvotes]: Problem: b) http://cl.ly/image/3a3l3142432M
Attempt:
I find the cost to be 458 000 $. See calculations in the link and/or my thoughts here:
Let cost be $c$.
$F_Z(\frac{c-500000}{50000})=0.2$ and then I find $z=0.84$ gives $P=0.8$ 
Thus $z=-0.84=\frac{c-500000}{50000}$
Am I right? I've got no solutions-manuel.

REPLY [0 votes]: \$457,918.90, or \$458,000 to three decimal places. Well done.
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