Homework help

#1
A box of cereal contains a mean of 13 ounces with a standard deviation of 0.5 ounces. The distribution of the contents is normal. What is the probability that a case of 12 cereal boxes contains a total of more than 160 ounces. (Answer to 4 decimal places)
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Let y = average content of boxes in the case
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y is modeled by N(13,0.5/√12)

Determine P(?160/12) [you determine whether ? is < or >]