Math Cafe Statistics and Probability

Discrete variable is from qualities that can be

• Measured

• Counted

• Both A and B

• none of these

Continuous variable is from qualities that can be

• Measured

• Counted

• Both A and B

• none of these

Which of the following is NOT a continuous variable?

• A person’s height each year

• A person’s weight on each birthday

• Number of Cars finished in a factory each day

• The volume of water in a swimming pool

Which of these is NOT a discrete variable?

• The number of students absent in a class

• The number of death per year attributed to lung cancer

• The average amount of electricity consumed per household

  per month

• The number of people who drive through a red light each

  hour during rush hour

The number of avocado produced by an avocado tree each year is a continuous variable

• True

• False

• Maybe

• Cannot be determined

If two coins are tossed, which is NOT a possible value of the random variable for the number of heads?

• 0

• 1

• 2

• 3

Which of the following is NOT a true statement?

• The value of a random variable could be zero.

• Random variables can only have one value.

• The probability of all the value of a random variable could be zero.

• The sum of all the probabilities in a probability distribution is always equal to one.

You decided to conduct a survey of families with two children. You are interested in counting the number of boys (out of 2 children) in each family. Is this a random variable? If it is, what are the possible values?

• Yes, it is a random variable and its value can be 1 or 2.

• Yes, it is a random variable and its value can be 0, 1 or 2.

• Yes, it is a random variable and its value can be 2 or 4.

• No, it is not a random variable since it is not random.

In a local community, a couples were asked the questions “Are you satisfied with the work of the current president?” If the husband and the wife both said “yes”, the response is written as YY. If the husband said yes and the wife said “no”, the response is YN. Let X = the number of “yes” responses. , what are the possible values of the random variables?

• 0, 1, 2

• 1, 2, 3

• 2, 3, 4

• 1, 1, 2

A quantity resulting from an experiment by chance, can assume a different values is called.

• Random Experiment

• Random Sample

• Random Variable

• Random process