Answer
a) Mean:145. Standard deviation:10.43.
b)It is not unusually high. Also, Mendel's theory seems to be true.
Work Step by Step
a) Mean=$n\cdot p=580 \cdot 0.25=145$.
Standard deviation: $\sqrt{n \cdot p \cdot (1-p)}=\sqrt{580 \cdot 0.25 \cdot 0.75}=10.43.$
b) If a value is unusual, then it is more than two standard deviations far from the mean. $Minimum \ usual \ value=mean-2\cdot(standard \ deviation)=145-2\cdot10.43=124.14$
$Maximum \ usual \ value=mean+2\cdot(standard \ deviation)=145+2\cdot10.43=165.86$.
152 is between these two values, therefore it is not unusually high. Also, Mendel's theory seems to be true.