Exercise 19.29, how many cod should be purchased if leftover fish can be sold to a fertilizer

Question:

Exercise 19.29, how many cod should be purchased if leftover fish can be sold to a fertilizer company for 30 cents each?
In exercise
The manager of a fish market pays 80 cents each for cod and sells them for $1.50 each. Fish left over at the end of the day are discarded. The daily demand can be approximated by a normal having a mean of 300 and a standard deviation of 50.
Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...