Answer:
Step-by-step explanation:
The probability distribution for the random variable X is provided.
X 4 5 6 7 Total
P 0.2 0.4 0.3 0.1 1
x*p 0.8 2 1.8 0.7 5.3
x^2*p 3.2 10 10.8 4.9 28.9
a) The expected value E(X), representing the mean of X, equates to 5.3.

Standard deviation is the square root of the variance, which amounts to 0.9.
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b) For the mean of the sample, we find:
Mean = 5.3
Variance = var(x)/n = 
c) 