pnorm(c(115, 110), mean = 110, sd = 4)
0.8943502 - 0.5000000
pnorm(105, mean = 110, sd = 4)
1- 0.1056498
pnorm(100, mean = 110, sd = 4)
qnorm(0.8, mean = 110, sd = 4)
rnorm(15, mean = 110, sd = 4)