ECON 262 Ch. 5

It is known that 10% of the calculators shipped from a particular factory are defective. What is the probability that exactly three of five chosen calculators are defective?

0.0081

It is known that 10% of the calculators shipped from a particular factory are defective. What is the probability that no more than one in a random sample of four calculators is defective?

0.6561

According to a study by the Centers for Disease Control and Prevention, about 33% of U.S. births are Caesarean deliveries. Suppose seven expectant mothers are randomly selected. What is the standard deviation of the number of mothers who will have a Caesarean delivery?

1.24

According to a study by the Centers for Disease Control and Prevention, about 33% of U.S. births are Caesarean deliveries. Suppose seven expectant mothers are randomly selected. The expected number of mothers who will not have a Caesarean delivery is ______.

4.69

What is a characteristic of the mass function of a discrete random variable X?

ALL OF THE ABOVE For every possible value x, the probability P(X = x) is between 0 and 1. Describes all possible values x with the associated probabilities P(X = x). The sum of probabilities P(X = x) over all possible values x is 1.

A Bernoulli process consists of a series of n independent and identical trials of an experiment such that in each trial there are three possible outcomes and the probabilities of each outcome remain the same.

FALSE

A discrete random variable X may assume an (infinitely) uncountable number of distinct values.

FALSE

The ounces of soda consumed by an adult next month are an example of a discrete random variable.

FALSE

Which of the following statements is the most accurate about a binomial random variable?

It counts the number of successes in a given number of trials.

A binomial random variable is defined as the number of successes achieved in n trials of a Bernoulli process.

TRUE

The expected value of a random variable X can be referred to as the population mean.

TRUE

Which of the following can be represented by a discrete random variable?

The number of defective light bulbs in a sample of five

Which of the following can be represented by a continuous random variable?

The time of a flight between Chicago and New York