Please help answer 2 short muliptly choice questions Thank y

Please help answer 2 short muliptly choice questions. Thank you.

-

1) Which of the following is correct?

A. A continuous random variable has a probability density function but not a cumulative distribution function.

B. A discrete random variable has a probability mass function but not a cumulative distribution function.

C. A continuous random variable has a probability mass function, and a discrete random variable has a probability density function.

D. A continuous random variable has a probability density function, and a discrete random variable has a probability mass function.

-

2) Which of the following is not a characteristic of a probability density function f(x)?

A. f(x) ? 0 for all values of x.

B. f(x) is symmetric around the mean.

C. The area under f(x) over all values of x equals one.

D. f(x) becomes zero or approaches zero if x increases to +infinity or decreases to -infinity.

Solution

1) Which of the following is correct?

D. A continuous random variable has a probability density function, and a discrete random variable has a probability mass function.

--------------------------------------------------------------------------------------------------------------------------

2) Which of the following is not a characteristic of a probability density function f(x)?

B. f(x) is symmetric around the mean.