SOLUTION: 3) Fidelity records the number of X-Trails sold each day. This data is used in calculating the following probability distribution of daily sales: x P(x) 0 0.1 1 0.1

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Question 1164019: 3) Fidelity records the number of X-Trails sold each day. This data is used in calculating the following probability distribution of daily sales:
x P(x)
0 0.1
1 0.1
2 0.2
3 0.2
4 0.3
5 0.1

a. Find the probability that the number sold tomorrow will be between 2 and four (inclusive)
b. Find the probability that the number sold tomorrow will be between 2 (inclusive) and four.
Please help me solve this question

Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website!

The answer to part A is 0.5
The answer to part B is 0.4

To get these answers, we add up the P(x) values. However, we only add up specific ones based on the restrictions mentioned.

Part A says "between 2 and four (inclusive)", which I interpret to mean . So x can't equal 2, but it can equal 4. This is the same as saying only when x is an integer. We'll be adding the P(x) values when x = 3 and x = 4, so we get 0.2+0.3 = 0.5

Part B says "between 2 (inclusive) and four", so we have now which is the same as only when x is an integer. We'll be adding the P(x) values when x = 2 and x = 3 to get 0.2+0.2 = 0.4