Question 1050517
u equals 81 and standard deviation o equals 4 
P(68 ≤ x ≤ 79) = normalcdf(68,79,81,4) Use Your Calculator
In general TI syntax is normalcdf(smaller, larger, µ, σ).
One could also Use a Casio fx-115 ES plus 0r fx-991 ES plus 
|
Recommend Using stattrek.com to check  Results
until You are familiar with Using Your Calculator.