Weight of a species of bird is normally distributed with a s

Weight of a species of bird is normally distributed with a standard deviation of 2 grams. If 30% of birds weigh less than 10 grams, what ist he population mean weight of these birds? Give your answer as a number without units.

Solution

P(Z<x) =0.3

x= -0.524

(10-mean)/2 = -0.524

mean = 11.048