Probability is the
a. number of successes divided by the number of failures.
b. numerical measure of the likelihood that an event will occur.
c. chance that an event will not happen.
d. number of successes divided by the standard deviation of the distribu
b. numerical measure of the likelihood that an event will occur.
A __________ describes the range and relative likelihood of all possible values for a random variable.
a. probability distribution for a random variable
b. probability mass function of an event
c. density function
d. probability
a. probability distribution for a random variable
An initial estimate of the probabilities of events is a __________ probability.
a. posterior
b. conditional
c. empirical
d. prior
d. prior
Sample space is
a. a process that results in some outcome.
b. the collection of all possible outcomes.
c. the collection of events
d. a subgroup of a population/the likelihood of an outcome.
b. the collection of all possible outcomes.
Two events are independent if
a. the two events occur at the same time.
b. the probability of one or both events is greater than 1.
c. P(A | B) = P(A) or P(B | A) = P(B).
d. None of these are correct.
c. P(A | B) = P(A) or P(B | A) = P(B).
Which statement is true about mutually exclusive events?
a. If events A and B cannot occur at the same time, they are called mutually exclusive.
b. If either event A or event B must occur, they are called mutually exclusive.
c. P(A) + P(B) = 1 for any eve
a. If events A and B cannot occur at the same time, they are called mutually exclusive.
A joint probability is the
a. sum of the probabilities of two events.
b. probability of the intersection of two events.
c. probability of the union of two events.
d. sum of the probabilities of two independent events.
b. probability of the intersection of two events.
A variable that can only take on specific numeric values is called a
a. categorical variable.
b. discrete random variable.
c. continuous random variable.
d. categorical variable.
b. discrete random variable.
An experiment consists of determining the speed of automobiles on a highway by the use of radar equipment. The random variable in this experiment is a
a. discrete random variable.
b. continuous random variable.
c. complex random variable.
d. categorical r
b. continuous random variable.
Which of the following statements is correct?
a. The binomial and normal distributions are both discrete probability distributions.
b. The binomial and normal distributions are both continuous probability distributions.
c. The binomial distribution is a c
d. The binomial distribution is a discrete probability distribution and the normal distribution is a continuous probability distribution.
Which of the following is a discrete random variable?
a. The number of times a student guesses the answers to questions on a certain test
b. The amount of gasoline purchased by a customer
c. The amount of mercury found in fish caught in the Gulf of Mexico
a. The number of times a student
All of the following are examples of discrete random variables except
a. number of tickets sold.
b. marital status.
c. time.
d. population of a city.
c. time.
The __________ probability distribution can be used to estimate the number of vehicles that go through an intersection during the lunch hour.
a. binomial
b. normal
c. triangular
d. Poisson
d. Poisson
The random variable X is known to be uniformly distributed between 2 and 12. Compute E(X), the expected value of the distribution.
a. 4
b. 5
c. 6
d. 7
d. 7
If a z-score is zero, then the corresponding x-value must be equal to the
a. mean.
b. median.
c. mode.
d. standard deviation.
a. mean.
16. In a normal distribution, which is greater, the mean or the median?
a. Mean
b. Median
c. Neither the mean or the median (they are equal)
d. Cannot be determined with the information provided
c. Neither the mean or the median (they are equal)
The center of a normal curve is
a. always equal to zero.
b. the mean of the distribution.
c. always a positive number.
d. equal to the standard deviation.
b. the mean of the distribution
Which of the following is not a characteristic of the normal probability distribution?
a. The mean, median, and the mode are equal.
b. The mean of the distribution can be negative, zero, or positive.
c. The distribution is symmetrical.
d. The standard dev
d. The standard deviation must be 1.
A health conscious student faithfully wears a device that tracks his steps. Suppose that the distribution of the number of steps he takes in a day is normally distributed with a mean of 10,000 and a standard deviation of 1,500 steps. What percent of the d
a. 2.28%
The newest model of smart car is supposed to get excellent gas mileage. A thorough study showed that gas mileage (measured in miles per gallon) is normally distributed with a mean of 75 miles per gallon and a standard deviation of 10 miles per gallon. Wha
a. 0.6%
A health conscious student faithfully wears a device that tracks his steps. Suppose that the distribution of the number of steps he takes in a day is normally distributed with a mean of 10,000 and a standard deviation of 1,500 steps. One day he took 15,00
c. 99.7%
The newest model of smart car is supposed to get excellent gas mileage. A thorough study showed that gas mileage (measured in miles per gallon) is normally distributed with a mean of 75 miles per gallon and a standard deviation of 10 miles per gallon. Wha
a. 75
A health conscious student faithfully wears a device that tracks his steps. Suppose that the distribution of the number of steps he takes is normally distributed with a mean of 10,000 and a standard deviation of 1,500 steps. How many steps would he have t
d. 12,467
What is the total area under the normal distribution curve?
a. It depends upon the mean and standard deviation
b. It must be calculated
c. 1
d. 100
c. 1
The triangular distribution is a good model for __________ distributions.
a. uniform
b. skewed
c. normal
d. normal
b. skewed