Random Variables

State why the example does or does not describe a random variable.

Label five slips of paper as A, B, C, D, and E. S is the random selection of a slip of paper.

• S is a random variable. A random variable is denoted with a capital letter.

• S is not a random variable, the outcome of the experiment is not numerical.

• S is a random variable. It has five possible outcomes.

• S is not a random variable. It is not determined by chance.

State why the example does or does not describe a random variable.

The letters "A", "B", "C", "D", "E", and "F" are written on six slips of paper, and the slips are placed into a hat. Assign A = 1, B = 2, C = 3, D = 4, E = 5 , and F = 6. S is the random selection of a slip of paper.

• S is a random variable. It has a single value for each outcome in an experiment.

• S is a random variable. A random variable is denoted with a capital letter.

• S is a random variable. It is not random.

• S is not a random variable. It is not determined by chance.

State whether the variable is discrete or continuous.

O represents the age of a single randomly chosen student from your classroom

• discrete random variable

• continuous random variable

• neither discrete random variable nor continuous random variable

A point is randomly selected from the interior of a square. Let x denote the distance from the lower left-hand corner A of the square to the selected point. Are the possible values of x a discrete or continuous variable?

• discrete random variable

• continuous random variable

• neither discrete random variable nor continuous random variable

Assume the “student” in the situation is chosen at random, and state whether the variable is discrete or continuous.

•The body temperature of the student.

• Discrete random variable

• Continuous random variable

• Neither discrete nor continuous

Assume the “student” in the situation is chosen at random, and state whether the variable is discrete or continuous.

•The student’s favorite teacher.

• Discrete random variable

• Continuous random variable

• Neither discrete nor continuous

Assume the “student” in the situation is chosen at random, and state whether the variable is discrete or continuous.

• The number of books the student has in his or her bag.

• Discrete random variable

• Continuous random variable

• Neither discrete nor continuous

True or False:

If the number of possible outcomes of a random variable is infinite but countable, the random variable is considered discrete.

• True

• False

Assume the “student” in the situation is chosen at random, and state whether the variable is discrete or continuous.

• The weight of the student.

• Discrete random variable

• Continuous random variable

• Neither discrete nor continuous

Choose a number between 1 and 10, multiply it by the age, in years, of the person next to you and add your own age in years. Do this for 5 people. B is the average of the results from the six trials. Is B a random variable?

• Yes

• No