Question

In: Statistics and Probability

Consider the following discrete probability distribution. x 15 22 34 40 P(X = x) 0.08 0.41...

Consider the following discrete probability distribution.

x 15 22 34 40
P(X = x) 0.08 0.41 0.28 0.23



a. Is this a valid probability distribution?


  • Yes, because the probabilities add up to 1.

  • No, because the gaps between x values vary.




b. What is the probability that the random variable X is less than 36? (Round your answer to 2 decimal places.)




c. What is the probability that the random variable X is between 12 and 27? (Round your answer to 2 decimal places.)




d. What is the probability that the random variable X is greater than 20? (Round your answer to 2 decimal places.)

Solutions

Expert Solution

Given

x 15 22 34 40
P(X=x) 0.08 0.41 0.28 0.23

a. Yes because the probabilities add up to 1.

i.e

In discrete probability distribution random variable x tells about what are the possibile values x can take with some probability assigned to x and these probabilities add up to 1.

Therefore sum of all probabilities of x should be equal to 1.

b.To find the probability that the random variable X is less than 36.

Therefore,

The probability that the random variable X is less than 36 is 0.77

c.​​​​​To find the probability that the random variable X is between 12 and 27.

Therefore,

The probability that the random variable X is between 12 and 27 is 0.49

d. To find the probability that the random variable X is greater than 20.

Therefore,

The probability that the random variable X is greater than 20 is 0.92.


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