Question

Which of the following is a valid probability value for a discrete random variable?

1) .2
2) 1.01
3) -.7
4) All of the above

Answer 1

The only valid probability value for a discrete random variable from the options given is .2, because it falls between zero and one inclusive, which are the requirements for a probability in a probability distribution function.

Step-by-step explanation:

The student is asking about the valid probability values for a discrete random variable. For a probability value to be valid, two conditions must be met based on the characteristics of a probability distribution function (PDF) of a discrete random variable:

1. The probability must be between zero and one, inclusive. This means it can be as low as zero or as high as one, but not below or above these values.
2. The sum of all the probabilities for the different outcomes must equal one.

Given the options

• .2 (this is between 0 and 1, so it is valid)
• 1.01 (this is greater than 1, so it is not valid)
• -.7 (this is less than 0, so it is not valid)

Therefore, the only valid probability value from the options provided is .2, or option 1).