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The following function is probability mass function of random variable X.

x -2 -1 0 1 2

f(x) 1/9 2/9 3/9 2/9 1/9

Determine the following probabilities. Give exact answers in form of fraction.


F(−2) = P(X ≤ −2) =



F(−1) = P(X ≤ −1) =



F(0) = P(X ≤ 0) =



F(1) = P(X ≤ 1 ) =



F(2) = P(X ≤ 2) =

2 Answers

5 votes

Final answer:

To calculate the probabilities F(−2), F(−1), F(0), F(1), and F(2), sum up the probabilities of all values less than or equal to the given value in the probability mass function.

Step-by-step explanation:

The probabilities F(−2), F(−1), F(0), F(1), F(2) can be calculated by summing up the probabilities of all values less than or equal to the given value in the probability mass function.

F(−2) = P(X ≤ −2) = 1/9

F(−1) = P(X ≤ −1) = 1/9 + 2/9 = 3/9

F(0) = P(X ≤ 0) = 1/9 + 2/9 + 3/9 = 6/9

F(1) = P(X ≤ 1) = 1/9 + 2/9 + 3/9 + 2/9 = 8/9

F(2) = P(X ≤ 2) = 1/9 + 2/9 + 3/9 + 2/9 + 1/9 = 9/9 = 1

User Vlk
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3 votes

Answer:

Step-by-step explanation:

To determine the probabilities, we need to calculate the cumulative distribution function (CDF) of the random variable X. The CDF of X gives the probability that X takes on a value less than or equal to a given value. We can calculate the CDF by summing up the probabilities for all values of X less than or equal to the given value.

For the given probability mass function:

x -2 -1 0 1 2

f(x) 1/9 2/9 3/9 2/9 1/9

To calculate F(-2), we need to sum the probabilities for all values less than or equal to -2:

F(-2) = P(X ≤ -2) = f(-2) = 1/9

To calculate F(-1), we need to sum the probabilities for all values less than or equal to -1:

F(-1) = P(X ≤ -1) = f(-2) + f(-1) = 1/9 + 2/9 = 3/9 = 1/3

To calculate F(0), we need to sum the probabilities for all values less than or equal to 0:

F(0) = P(X ≤ 0) = f(-2) + f(-1) + f(0) = 1/9 + 2/9 + 3/9 = 6/9 = 2/3

To calculate F(1), we need to sum the probabilities for all values less than or equal to 1:

F(1) = P(X ≤ 1) = f(-2) + f(-1) + f(0) + f(1) = 1/9 + 2/9 + 3/9 + 2/9 = 8/9

To calculate F(2), we need to sum the probabilities for all values less than or equal to 2:

F(2) = P(X ≤ 2) = f(-2) + f(-1) + f(0) + f(1) + f(2) = 1/9 + 2/9 + 3/9 + 2/9 + 1/9 = 9/9 = 1

Therefore, the exact probabilities are:

F(-2) = P(X ≤ -2) = 1/9

F(-1) = P(X ≤ -1) = 1/3

F(0) = P(X ≤ 0) = 2/3

F(1) = P(X ≤ 1) = 8/9

F(2) = P(X ≤ 2) = 1

User Lakshmi Swetha G
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7.8k points