BANA EXAM 2
An experiment consists of four outcomes with P(E 1) = 0.2, P(E 2) = 0.3, and P(E 3) = 0.4. The probability of outcome E 4 is
0.100
If A and B are independent events with P(A) = 0.2 and P(B) = 0.6, then P(A union B) =
0.68
The assembly time for a product is uniformly distributed between 6 to 10 minutes.The expected assembly time (in minutes) is(Round your answer to one decimal place.)
8.0
The Poisson probability distribution is used with _____ random variable.
a discrete
The number of customers that enter a store during one day is an example of
a discrete random variable.
A normal distribution with a mean of 0 and a standard deviation of 1 is called
a standard normal distribution
A probability distribution showing the probability of x successes in n trials, where the probability of success does not change from trial to trial, is termed a
binomial probability distribution.
The binomial probability distribution is used with a(n) _____ random variable.
discrete
A random variable that can assume only a finite number of values is referred to as a(n)
discrete random variable
In a binomial experiment, the probability
does not change from trial to trial.
What is a collection of sample points called?
event
A measure of the average value of a random variable is called a(n)
expected value.
A continuous probability distribution that is useful in describing the time, or space, between occurrences of an event is a(n) _____ probability distribution.
exponential
The probability distribution that can be described by just one parameter is the
exponential
There is a lower limit but no upper limit for a random variable that follows the _____ probability distribution.
exponential
The _____ probability function is based in part on the counting rule for combinations.
hypergeometric
To compute the probability that in a random sample of n elements, selected without replacement, we will obtain x successes, we would use the _____ probability distribution.
hypergeometric
A sample point refers to the
individual outcome of an experiment
The symbol ∩ shows the
intersection of two events.
A normal probability distribution
is a continuous probability distribution.
The probability that a continuous random variable takes any specific value
is equal to zero
The center of a normal curve
is the mean of the distribution.
The intersection of two mutually exclusive events
must always be equal to 0.
The company identified in Chapter 5, Statistics in Practice is
not a company but precinct polling locations
The Statistics in Practice example in Chapter 4 is primarily concerned with
part failures
The counting rule that is used for counting the number of experimental outcomes when n objects are selected from a set of N objects where order of selection is important is called the counting rule for
permutations.
The Statistics in Practice example in Chapter 5 focuses on
polling booths or machines
Initial estimates of the probabilities of events are known as _____ probabilities
prior
Chapter 4 focuses on
probability
The function that defines the probability distribution of a continuous random variable is a
probability density function
Chapter 5 focuses on
probability distributions
Chapter 6 focuses on
probability distributions
The key difference between the binomial and hypergeometric distribution is that, with the hypergeometric distribution, the
probability of success changes from trial to trial.
A graphical method of representing the sample points of an experiment is a
tree diagram
The symbol ∪ shows the
union of events.
A graphical representation in which the sample space is represented by a rectangle and events are represented as circles is called a
venn diagram
Larger values of the standard deviation result in a normal curve that is
wider and flatter.
The addition law is potentially helpful when we are interested in computing the probability of
the union of two events.
General Hospital has noted that they admit an average of 8 patients per hour. Assuming a Poisson distribution, what is the probability that during the next two hours exactly 8 patients will be admitted? (Round your answer to three decimal places.)
.012
General Hospital has noted that they admit an average of 8 patients per hour. Assuming a Poisson distribution, what is the probability that during the next hour less then 3 patients will be admitted? (Round your answer to three decimal places.)
.014
The weight of football players for a team is normally distributed with a mean of 275 pounds and a standard deviation of 50 pounds.The probability of a player weighing more than 350 pounds is
.067
The student body of a large university consists of 60% female students. A random sample of 8 students is selected.What is the probability that among the students in the sample exactly four are female? Use an Excel function and round your answer to three decimal places
.232
According to the article in this Module, the probability of winning a prize at the in-store McDonald's Monopoly game was
.25
The time required to load a truck is exponentially distributed with a mean of 15 minutes. What is the probability that a truck will be loaded in 10 to 20 minutes? Enter your answer as a decimal not as a percent and round your answer to 3 decimal places.
.252
The time required to load a truck is exponentially distributed with a mean of 15 minutes. What is the probability that a truck will be loaded in 20 minutes or more? Enter your answer as a decimal not as a percent and round your answer to 3 decimal places.
.264
The student body of a large university consists of 60% female students. A random sample of 8 students is selected.What is the probability that among the students in the sample at most four are female? Use an Excel function and round your answer to three decimal places.
.406
The time required to load a truck is exponentially distributed with a mean of 15 minutes. What is the probability that a truck will be loaded in 10 minutes or less? Enter your answer as a decimal not as a percent and round your answer to 3 decimal places.
.487
The assembly time for a product is uniformly distributed between 6 to 10 minutes.The probability of assembling the product between 7 to 9 minutes is(Round your answer to two decimal places.)
.50
The student body of a large university consists of 60% female students. A random sample of 8 students is selected.What is the probability that among the students in the sample more than four are female? Use an Excel function and round your answer to three decimal places
.594
Forty percent of the students who enroll in a statistics course go to the statistics laboratory on a regular basis. Past data indicates that 55% of those students who use the lab on a regular basis make a grade of A in the course. On the other hand, only 25% of students who do not go to the lab on a regular basis make a grade of A. If a particular student made an A, determine the probability that she or he used the lab on a regular basis. (Round your answer to three decimal places.)
.595
The student body of a large university consists of 60% female students. A random sample of 8 students is selected.What is the probability that among the students in the sample at least four are female? Use an Excel function and round your answer to three decimal places.
.826
The life expectancy of computer terminals is normally distributed with a mean of 4 years and a standard deviation of 1 year. What is the probability that a terminal will last 5 years or less? Use Excel and round your answer to three decimals.
.841
The range of probability is
0-1
The assembly time for a product is uniformly distributed between 6 to 10 minutes.The probability of assembling the product in less than 6 minutes is(Round your answer to one decimal place.)
0.0
If A and B are mutually exclusive events with P(A) = 0.295, P(B) = 0.32, then P(A | B) =
0.0000
In a standard normal distribution, what is the probability that z is greater than zero?
0.5
The sum of the probabilities of two complementary events is
1.0
Simple random sampling uses a sample of size n from a population of size N to obtain data that can be used to make inferences about the characteristics of a population. Suppose that, from a population of 50 bank accounts, we want to take a random sample of four accounts in order to learn about the population. How many different random samples of four accounts are possible?
230300
An experiment consists of three steps. There are four possible results on the first step, three possible results on the second step, and two possible results on the third step. The total number of experimental outcomes is
24
The student body of a large university consists of 60% female students. A random sample of 8 students is selected.What is the expected number of females selected? Round your answer to one decimal place.
4.8
Which of the following is not a characteristic of the normal probability distribution?
99.72% of the time the random variable assumes a value within plus or minus 1 standard deviation of its mean.
The union of events A and B is the event containing all the sample points belonging to
A or B or both
According to Perfect Payday, Jeffrey Rich was
CEO of Affiliated Computer Services
Which of the following is a characteristic of an experiment where the binomial probability distribution is applicable?
Exactly two outcomes are possible on each trial.
The company identified in Chapter 4, Statistics in Practice is
NASA
A decision maker subjectively assigned the following probabilities to the four outcomes of an experiment: P(E1) = 0.05, P(E2) = 0.10, P(E3) = 0.40, and P(E4) = 0.40. Are these probability assignments valid? Explain.
No, the probabilities do not sum to 1.
What is the complement of P(A|B)?
P(A^C|B)
When dealing with the number of occurrences of an event over a specified interval of time or space, the appropriate probability distribution is a _____ distribution.
Poisson
In the textile industry, a manufacturer is interested in the number of blemishes or flaws occurring in each 100 feet of material. The probability distribution that has the greatest chance of applying to this situation is the
Poisson distribution
The company identified in Chapter 6, Statistics in Practice is
Proctor & Gamble
The z score for the standard normal distribution
can be either negative or positive.
A normal probability distribution
can have a mean of any numerical value.
Two events with nonzero probabilities
cannot be both mutually exclusive and independent
The standard deviation of a normal distribution
cannot be negative.
When the assumption of equally likely outcomes is used to assign probability values, the method used to assign probabilities is referred to as the _____ method.
classical
The counting rule that is used for counting the number of experimental outcomes when n objects are selected from a set of N objects where order of selection is not important is called the rule for
combinations.
Posterior probabilities are _____ probabilities.
conditional
A numerical description of the outcome of an experiment is called a
random variable.
The Statistics in Practice example in Chapter 6 identifies an application concerned with
raw material prices
When the results of experimentation or historical data are used to assign probability values, the method used to assign probabilities is referred to as the _____ method.
relative frequency
A method of assigning probabilities based upon judgment is referred to as the _____ method.
subjective
The probability of an event is the _____ of the probabilities of the sample points in the event.
sum
The highest point of a normal curve occurs at
the mean.
A negative value of z indicates
the number of standard deviations an observation is to the left of the mean.
Bayes' theorem is used to compute
the posterior probabilities.
If two events are independent, then
the product of their probabilities gives their intersection.
The collection of all possible sample points in an experiment is
the sample space