Stats chapter 5 vocabulary

Refer to Exhibit 5-8. The probability that there are less than 3 occurrences is

.1016

The variance of the number of days Pete will catch fish is

.48

A production process produces 2% defective parts. A sample of five parts from the production process is selected. What is the probability that the sample contains exactly two defective parts?

0.0038

Four percent of the customers of a mortgage company default on their payments. A sample of five customers is selected. What is the probability that exactly two customers in the sample will default on their payments?

0.0142

Exhibit 5-2The student body of a large university consists of 60% female students. A random sample of 8 students is selected.48. Refer to Exhibit 5-2. What is the probability that among the students in the sample exactly two are female?

0.0413

Refer to Exhibit 5-2. What is the probability that among the students in the sample at least 6 are male?

0.0499

Refer to Exhibit 5-10. What is the probability that in a given game the Lions will score no goals?

0.05

In a binomial experiment the probability of success is 0.06. What is the probability of two successes in seven trials?

0.0555

Refer to Exhibit 5-10. What is the probability that in a given game the Lions will score less than 3 goals?

0.55

The following represents the probability distribution for the daily demand of computers at a local store.Demand Probability0 0.11 0.22 0.33 0.24 0.246. Refer to Exhibit 5-1. The expected daily demand is

2.2

X is a random variable with the probability function:f(X) = X/6 for X = 1, 2 or 3The expected value of X is

2.333

exhibit 5-10The probability distribution for the number of goals the Lions soccer team makes per game is given below.NumberOf GoalsProbability0 0.051 0.152 0.353 0.304 0.15 Refer to Exhibit 5-10. The expected number of goals per game is

2.35

Refer to Exhibit 5-7. The expected number of days Pete will catch fish is

2.4

Probability Distribution x f(x)10 .220 .330 .440 .1 Refer to Exhibit 5-5. The expected value of x equals

24

The expected value for a binomial probability distribution is

E(x) = nP

The weight of an object is an example of

a continuous random variable

The Poisson probability distribution is used with

a discrete random variable

The binomial probability distribution is used with

a discrete random variable

The number of customers that enter a store during one day is an example of

a discrete random variable

Variance is..

a measure of the dispersion of a random variable

A continuous random variable may assume

any value in an interval or collection of intervals

A local bottling company has determined the number of machine breakdowns per month and their respective probabilities as shown below: Number ofBreakdownsProbability0 0.121 0.382 0.253 0.184 0.07 Refer to Exhibit 5-11. The expected number of machine breakdowns per month is

170

Refer to Exhibit 5-3. The variance is

2.047

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

If you are conducting an experiment where the probability of a success is .02 and you are interested in the probability of 4 successes in 15 trials, the correct probability function to use is the

binomial probability function

A random variable that may take on any value in an interval or collection of intervals is known as a

continuous 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

continuous random variable

Refer to Exhibit 5-8. The appropriate probability distribution for the random variable is

discrete

When sampling without replacement, the probability of obtaining a certain sample is best given by a

hypergeometric distribution

The expected value of a discrete random variable

is the average value for the random variable over many repeats of the experiment

The expected value of a random variable is

mean value of a random variable

A weighted average of the value of a random variable, where the probability function provides weights is known as

the expected value

In a binomial experiment

the probability does not change from trial to trial

The key difference between the binomial and hypergeometric distribution is that with the hypergeometric distribution

the probability of success changes from trial to trial

Which of the following is not a characteristic of an experiment where the binomial probability distribution is applicable?

the trials are dependent

Which of the following is a characteristic of a binomial experiment?

the trials are independent

Which of the following is not a property of a binomial experiment?

the trials are independent

The variance for the binomial probability distribution is

var(x) = nP(1 - P)

Assume that you have a binomial experiment with p = 0.4 and a sample size of 50. The variance of this distribution is

12

Refer to Exhibit 5-8. The probability that there are 8 occurrences in ten minutes is

.0771

The probability that Pete will catch fish when he goes fishing is .8. Pete is going to fish 3 days next week. Define the random variable X to be the number of days Pete catches fish. Refer to Exhibit 5-7. The probability that Pete will catch fish on exactly one day is

.096

Exhibit 5-9The probability distribution for the daily sales at Michael's Co. is given below.Daily Sales(In $1,000s)Probability40 0.150 0.460 0.370 0.2 Refer to Exhibit 5-9. The expected daily sales are

56000

Which of the following is a required condition for a discrete probability function?

f(x) = 1 for all values of x

Refer to Exhibit 5-7. The probability that Pete will catch fish on one day or less is

.104

Refer to Exhibit 5-4. The probability that there are no females in the sample is

0.0778

Refer to Exhibit 5-2. What is the probability that among the students in the sample at least 7 are female?

0.1064

Refer to Exhibit 5-11. The probability of no breakdowns in a month is

0.12

Refer to Exhibit 5-12. What is the probability that in a given day there will be no accidents?

0.15

Refer to Exhibit 5-11. The probability of at least 3 breakdowns in a month is

0.25

The number of electrical outages in a city varies from day to day. Assume that the number of electrical outages (x) in the city has the following probability distribution. x f(x)0 0.801 0.152 0.043 0.01

0.26 and 0.577

Exhibit 5-4Forty percent of all registered voters in a national election are female. A random sample of 5 voters is selected. 54. Refer to Exhibit 5-4. The probability that the sample contains 2 female voters is

0.3456

Refer to Exhibit 5-13. The standard deviation for the production is

0.612

Refer to Exhibit 5-1. The probability of having a demand for at least two computers is

0.7

he police records of a metropolitan area kept over the past 300 days show the following number of fatal accidents. Number of Fatal Accidents Number of Days0 451 752 1203 454 15 Refer to Exhibit 5-12. What is the probability that in a given day there will be less than 3 accidents?

0.8

Refer to Exhibit 5-12. What is the probability that in a given day there will be at least 1 accident?

0.85

Refer to Exhibit 5-9. The probability of having sales of at least $50,000 is

0.90

Refer to Exhibit 5-10. What is the probability that in a given game the Lions will score at least 1 goal?

0.95

Refer to Exhibit 5-6. The variance of the number of cups of coffee is

0.96

A sample of 2,500 people was asked how many cups of coffee they drink in the morning. You are given the following sample information.Cups of Coffee Frequency0 7001 9002 6003 3002,500 Refer to Exhibit 5-6. The expected number of cups of coffee is

1.2

Refer to Exhibit 5-3. The standard deviation is

1.431

Exhibit 5-3Roth is a computer-consulting firm. The number of new clients that they have obtained each month has ranged from 0 to 6. The number of new clients has the probability distribution that is shown below.Number ofNew Clients Probability0 0.051 0.102 0.153 0.354 0.205 0.106 0.0551. Refer to Exhibit 5-3. The expected number of new clients per month is

3.05

Oriental Reproductions, Inc. is a company that produces handmade carpets with oriental designs. The production records show that the monthly production has ranged from 1 to 5 carpets. The production levels and their respective probabilities are shown below.ProductionPer Month Probabilityx f(x)1 0.012 0.043 0.104 0.805 0.05 Refer to Exhibit 5-13. the expected monthly production level is

3.84

Twenty percent of the students in a class of 100 are planning to go to graduate school. The standard deviation of this binomial distribution is

4

Refer to Exhibit 5-8. The expected value of the random variable x is

5.3

Assume that you have a binomial experiment with p = 0.5 and a sample size of 100. The expected value of this distribution is

50

Refer to Exhibit 5-5. The variance of x equals

84

The standard deviation of a binomial distribution is

None of these alternatives is correct

The hypergeometric probability distribution is identical to

None of these alternatives is correct.

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

When dealing with the number of occurrences of an event over a specified interval of time or space, the appropriate probability distribution is a

Poisson distribution

Which of the following statements about a discrete random variable and its probability distribution are true?

Values of f(x) must be greater than or equal to zero.

The Poisson probability distribution is a

discrete probability distribution

A random variable that can assume only a finite number of values is referred to as a(n)

discrete random variable

An experiment consists of making 80 telephone calls in order to sell a particular insurance policy. The random variable in this experiment is a

discrete random variable

Which of the following is a characteristic of an experiment where the binomial probability distribution is applicable?

exactly two outcomes are possible for each trial

A measure of the average value of a random variable is called a(n)

expected value

Which of the following is not a required condition for a discrete probability function?

f(x) = 0 for all values of x

Exhibit 5-8The random variable x is the number of occurrences of an event over an interval of ten minutes. It can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. It is known that the mean number of occurrences in ten minutes is 5.3. The random variable x satisfies which of the following Discrete Probability Distributions?

poisson

The standard deviation is the

positive square root of the variance

A description of the distribution of the values of a random variable and their associated probabilities is called a

probability distribution

A numerical description of the outcome of an experiment is called a

random variable

The variance is a measure of dispersion or variability of a random variable. It is a weighted average of the

squared deviations from the mean