Originally Posted by
lalalamaths please help me! i am a little bit stuck!
a farmer supplies tomatoes to a grocery, with an average weight of 74 grams
weight of tomatoes is normally distributed about their mean
grocery has policy of rejecting tomatoes that weigh less than 70 grams
11% of the farmer's tomatoes have been rejected
what is the standard deviation?
i know z=(x-mean)/stdev, x=70, mean=74, P(X<70)=0.11 but i'm totally mind-blanking on how to find z and also stdev.
i think P(x<70)=P(Z<z), is that right?
any help is very much appreciated!
many thanks!!