Answer
a) $0.70$
b) $0.11$
Work Step by Step
a) We find:
$μ=np=(64)(0.8)=51.2 $
$σ=\sqrt{npq}=\sqrt{(64)(0.8)(0.2)}=32$
Hence, we find z:
$z=\frac{49.5−51.2}{3.2}=−0.53$
Thus, using the table of z-scores, we can find that the corresponding probability is: $1−0.3=0.7$.
b) We find the second z:
$z=\frac{50.5−51.2}{3.2}=−0.22$
Thus, using the table of z-scores, we can find that the corresponding probability is: $0.41−0.3=0.11$.
