(1)
Formula for the variance is given by:
If we don't square the (x-):
Sum of the deviations from mean is zero.
i.e.,
So,
Answer is:
0
(b)
Binomial Distribution
n = 25
p = 0.20
q = 1 - p = 0.80
(i) Mean = np = 25 X 0.20 = 5
(ii) Standard Deviation =
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