2 Given x Px 4 040 7 025 10 035 a List ALL the conditio

2. Given

x | P(x)

– 4 | 0.40

7 | 0.25

–10 | 0.35

a. List ALL the conditions that shown above is a probability distribution.

b. Find the mean of the probability distribution.

c. Find the standard deviation.

Solution

a) P(X) >0

ii) Total prob = 0.40+0.25+0.35 = 1

Hence all conditions are satisfied hence a prob distribution

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b) To find mean and std dev

Hence Mean of x = -3.35

E(X^2) = 53.65

Var(X) = 53.65-3.35²

=42.4275

Std dev(X) = 6.514