The sample mean is μ=80, and sample standard deviation is σₓ=[tex] \frac{σ}{\sqrt{n}} =\frac{16}{\sqrt{64}} =2 [/tex].
The Z-score is [tex] Z=\frac{ 82.8-80}{2}=1.4 [/tex].
Refer to standard normal distribution table.
The required probability is
[tex] P(X<82.8)=P(Z<1.4)=0.9192 [/tex]
