Hi,
mean of 60 and a standard deviation of 8
Using TI: The syntax is normalcdf(smaller, larger, µ, σ).
P(44 ≤ x ≤ 68) = normalcdf(44,68,60,8)
P(52≤ x ≤ 76) = normalcdf(52,76,60,8)
0r
P(44 ≤ x ≤ 68) = NORMSDIST(1) - NORMSDIST(-2) = .8413 - .0228
P(52≤ x ≤ 76) = NORMSDIST(2) - NORMSDIST(-1) = .9772 - .1587