The sample mean is μ=78, and sample standard deviation is σₓ=σ/[tex] \sqrt{n} [/tex]=16/[tex] \sqrt{64} [/tex]=2.
The Z-score is [tex] Z=\frac{80.8-78}{2} =1.4 [/tex].
The required probability
[tex] P(X<80.8)=P(Z<1.4) [/tex]
Refer to standard normal distribution table.
[tex] P(Z<1.4)=0.9192 [/tex]
