=+37. Parameters. Every Normal model is defined by its parameters, the mean and the standard deviation. For each model described here, find the missing parameter. As always, start by drawing a picture.

a) m = 20, 45% above 30; s = ?

b) m = 88, 2% below 50; s = ?

c) s = 5, 80% below 100; m = ?

d) s = 15.6, 10% above 17.2; m = ?