1) Find the mean of the discrete random variable with the probability distribution below.
X: 5 9 12 14 19
P(x): 0.2 0.15 0.1 0.3 0.25
2) Find the mean of the discrete random variable with the probability distribution below.
X: 1 2 3 4 5
p(X): 0.65 0.1 0.05 0.15 0.05
X: 5 9 12 14 19
P(x): 0.2 0.15 0.1 0.3 0.25
2) Find the mean of the discrete random variable with the probability distribution below.
X: 1 2 3 4 5
p(X): 0.65 0.1 0.05 0.15 0.05
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The expected value (mean) is defined as this
E[X] = ∑ x * p(x) for all x
so
Question # 1
E[X] = 5 * 0.2 + 9 * 0.15 + 12 * 0.1 + 14 * 0.30 + 19 * 0.25
= 1 + 1.35 + 1.2 + 4.2 + 4.75
= 12.5
Answer: mean = 12.5
Question # 2
Do the same thing I did above [multiply each 'x' value with its corresponding probability [p(x)] and add up all of these products to get the mean (expected value).
For question # 2 I get
E[X] = 1.85 [you can check this though by doing the steps I did for Question #1]
E[X] = ∑ x * p(x) for all x
so
Question # 1
E[X] = 5 * 0.2 + 9 * 0.15 + 12 * 0.1 + 14 * 0.30 + 19 * 0.25
= 1 + 1.35 + 1.2 + 4.2 + 4.75
= 12.5
Answer: mean = 12.5
Question # 2
Do the same thing I did above [multiply each 'x' value with its corresponding probability [p(x)] and add up all of these products to get the mean (expected value).
For question # 2 I get
E[X] = 1.85 [you can check this though by doing the steps I did for Question #1]