Hi
normally distributed with a mean of 20 grams with a standard deviation of 0.15 grams.
P(x > 19.805) = 1 -P(x ≤ 19.805) = 1 - normalcdf(-9999, 19.805, 20, .15)= 1-.0968 = .9032 = .90
P(x < 20.06) = normalcdf(-9999, 20.06, 20, .15) = .6554 = .66
P( 19.805 < x < 20.06) = normalcdf(19.805,20, 20, .15)= .4032 = .40
83 % of all mice have a mass of less than grams. invNorm(.83) = .9542
OR
.15* .9542 + 20 < 20.14 g
Wish You the Best in your Studies.