I'm doing some revision and i came across this question and i can't work out how to start it.

In a food manufacturing plant, the weight of cereal is normally distributed with a mean of 200.6 gms and a standrad deviation of 1.8Gms.

Assuming the same standard deviation, how large would the mean weight have to be in order for less than 1% of packets to be rejected as underfilled.

packets are rejects if they are under 198 gms.


HELP this is driving me mental!