Chapter 6, Problem 1RE

(a)

To determine

Random variable.

Answer to Problem 1RE

Solution: It is a discrete random variable.

Explanation of Solution

A variable with only countable number of values is known as a discrete random variable. The number of students is countable, so it is a discrete random variable.

To determine

To obtain: The number of randomly selected students of the class.

Answer to Problem 1RE

Solution: The possible values of the random variable can be $X=1,2,3$, and so on.

Explanation of Solution

Hence, the number of students is not provided in the problem, so it can take any values from 1, 2, 3, and so on.

(b)

To determine

Random variable.

Answer to Problem 1RE

Solution: It is continuous random variable.

Explanation of Solution

A variable where data can take many values infinitely is known as a continuous random variable. The number of snowfalls can take any value, so it is a continuous random variable.

To determine

To obtain: The amount of snowfalls.

Answer to Problem 1RE

Solution: The possible quantity of snowfalls can take any value from 0 to infinity inches.

Explanation of Solution

Hence, the quantity of snowfalls is not provided in the problem, so it can take any values from 0 to infinity inches.

(c)

To determine

Random variable.

Answer to Problem 1RE

Solution: It is a continuous random variable.

Explanation of Solution

A variable where data can take many values infinitely is known as a continuous random variable. The flight time can take any value, so it is a continuous random variable.

To determine

To obtain: The flight time.

Answer to Problem 1RE

Solution: The time of flight can take any value from 00:00:00 to 24:00:00 hours.

Explanation of Solution

Hence, the flight times are not provided in the problem, so it can take any values from 00:00:00 to 24:00:00 hours.

(d)

To determine

Random variable.

Answer to Problem 1RE

Solution: It is discrete random variable.

Explanation of Solution

A variable with only countable number of values is known as a discrete random variable. The number of basketball points is countable, so it is a discrete random variable.

To determine

To obtain: Basketball points.

Answer to Problem 1RE

Solution: The possible number of basketball points in any day can be $X=1,2,3,$ and so on.

Explanation of Solution

Hence, the number of basketball points is not provided in the problem, so it can take any values from 1, 2, 3, and so on.