Question

1.      The height of grade 1 pupils is approximately normally distributed with µ = 45 inches and s = 2. a.      If a pupil is selected at random, what is the probability that is taller than 46 inches?

Answer 1

$Z=\frac{X-\mu}{\sigma}$

$P(X>46)=1-P(X<46)$

$=1-P(Z<\frac{46-45}{2})$

$=1-P(Z<0.5)$

$=1-0.6915=0.3085$