Concept:For a binomial distribution, the mean is
np and the mode is approximately
np; they are equal when the distribution is symmetric, i.e., when
p=0.5 (or
q=0.5).
Explanation:Mean
=np.
Mode is the most probable value; for binomial, mode lies near
np.
When
q=0.5, then
p=0.5.
For
p=0.5, the distribution is symmetric about
n/2.
If
n is even, mean
= mode
=n/2.
Even when
n is odd, the two modes are symmetric about the mean, and many textbooks state the property as "mean = mode when
p=0.5".
Thus, the correct option is C.
Answer: