Chapter 6 and Chapter 7

Question 1

A continuous probability distribution for which the probability that the random variable will assume a value in any interval is the same for each interval of equal length.

Answer 1

Uniform Probability Distribution

Question 2

A continuous probability distribution that has a probability density function that is bell-shaped and determine by its mean μ and standard deviation σ.

Answer 2

Normal Probability Distribution

Question 3

A normal distribution what a mean of zero and a standard deviation of one.

Answer 3

Standard Normal Probability Distribution

Question 4

A continuous probability distribution that is useful in computing probabilities for the time it takes to complete a task.

Answer 4

Exponential Probability Distribution

Question 5

A function used to compute probabilities for a continuous random variable. The area under the graph of this function over an interval represents probability.

Answer 5

Probability Density Function

Question 6

A numerical characteristic of a population, such as a population mean μ, a population standard deviation σ, a population proportion p, etc.

Answer 6

Parameter

Question 7

A sample characteristic, such as a sample mean x bar, a sample standard deviation s, a sample proportion p bar, etc.

Answer 7

Sample Statistic

Question 8

The value of a sample statistic used in a particular instance as an estimate of a population parameter.

Answer 8

Point Estimate

Question 9

A property of a point estimator that is present when the expected value of the point estimator is equal to the population parameter it estimates.

Answer 9

Unbiased

Question 10

The population for which the statistical inferences such as point estimates are made.

Answer 10

Target Population

Question 11

The population from which the sample is taken.

Answer 11

Sampled Population

Question 12

A property of a point estimator that is present whenever larger sample sizes tend to provide point estimates closer to the population parameter.

Answer 12

Consistency

Question 13

Given two unbiased point estimators of the same population parameter, the point estimator with the smaller standard error is more efficient.

Answer 13

Relative Efficiency

Question 14

The population from which the sample is taken.

Answer 14

Sampled Population

Question 15

Once an element has been included in the sample, it is returned to the population. A previously selected element can be selected again and therefore may appear in the sample more than once.

Answer 15

Sampling with Replacement

Question 16

Once an element has been included in the sample, it is removed from the population and cannot be selected a second time.

Answer 16

Sampling without Replacement

Question 17

A sample of size n from a finite population of size N is selected such that each possible sample of size n has the same probability of being selected.

Answer 17

Simple Random Sample

Question 18

A probability sampling method in which the population is first divided into strata and a simple random sample is then taken from each stratum.

Answer 18

Stratified Random Sampling

Question 19

A probability sampling method in which we randomly select one of the first k elements and then select every kth element thereafter.

Answer 19

Systematic Sampling

Question 20

A probability sampling method in which the population is first divided into clusters and then a simple random sample of the clusters is taken.

Answer 20

Cluster Sampling

Question 21

A nonprobability method of sampling whereby elements are selected for the sample on the basis of ease of collection.

Answer 21

Convenience Sampling

Question 22

A nonprobability method of sampling whereby elements are selected for the sample based on the expertise of the person doing the study.

Answer 22

Judgment Sampling

Question 23

A probability distribution consisting of all possible values of a sample statistic.

Answer 23

Sampling Distribution

Question 24

The standard deviation of a point estimator.

Answer 24

Standard Error

Question 25

The term that is used in the formulas whenever a finite population, rather than an infinite population, is being sampled.

Answer 25

Finite Population Correction Factor

Question 26

A theorem that enables one to use the normal probability distribution to approximate the sampling distribution of the sample mean whenever the sample size is large.

Answer 26

Central Limit Theorem

Question 27

The Excel function that returns the standard normal distribution.

Answer 27

NORM.S.DIST

Question 28

The Excel function that returns the inverse of the standard normal cumulative distribution.

Answer 28

NORM.S.INV

Question 29

The Excel function that returns the normal distribution for the specified mean and standard deviation.

Answer 29

NORM.DIST

Question 30

The Excel function that returns the inverse of the normal cumulative distribution for the specified mean and standard deviation.

Answer 30

NORM.INV

Question 31

The Excel function that returns the exponential distribution.

Answer 31

EXPON.DIST

Question 32

The Excel function that rounds a number down.

Answer 32

ROUNDDOWN

Question 33

The Excel function that rounds a number up.

Answer 33

ROUNDUP

Question 34

The Excel function that returns a random number greater than or equal to 0 and less than 1, evenly distributed.

Answer 34

RAND()

Question 35

Name 3 continuous probability distributions.

Answer 35

Uniform Probability Distribution Normal Probability Distribution Exponential Probability Distribution

Question 36

``` f(x) = 1/(b-a) for a <= x <=b f(x) = 0 elsewhere ```

Answer 36

Uniform Probability Density Function

Question 37

E(x) = (a+b)/2

Answer 37

Expected Value of a Uniform Probability Distribution

Question 38

Var(x) = (b-a)^2 / 12

Answer 38

Variance of a Uniform Probability Distribution

Question 39

The most important distribution for describing a continuous random variable. It is widely use in statistical inference for applications such as heights of people, tests scores, rainfall amounts, scientific measurements, etc.

Answer 39

Normal Probability Distribution

Question 40

Which probability distribution has a skewness measure of zero (i.e. it is symmetric).

Answer 40

Normal Probability Distribution

Question 41

Normal probability distributions are defined by its _________ and ___________ .

Answer 41

Mean | Standard Deviation

Question 42

The highest point on the normal curve is at the _______ / _______ / _______ .

Answer 42

Mean Median Mode

Question 43

The _________ determines the width of the normal curve.

Answer 43

Standard Deviation

Question 44

The empirical rule states that _____ % of values of a normal random variable are within +/- 1 standard deviation of its mean.

Answer 44

68%

Question 45

The empirical rule states that _____ % of values of a normal random variable are within +/- 2 standard deviation of its mean.

Answer 45

95%

Question 46

The empirical rule states that _____ % of values of a normal random variable are within +/- 3 standard deviation of its mean.

Answer 46

99.7%

Question 47

The letter ___ is used to designate the standard normal random variable.

Answer 47

z

Question 48

z = (x-μ)/σ

Answer 48

The formula for z-scores. Used to convert a normal probability distribution to a standard normal probability distribution.

Question 49

The probability distribution used to describe time between vehicle arrivals at a toll booth, time required to complete a questionnaire, distance between major defects in a highway, etc.

Answer 49

Exponential Probability Distribution

Question 50

For an exponential distribution, the ________ and ________ are equal.

Answer 50

Mean | Standard Deviation

Question 51

The probability distribution that is skewed to the right.

Answer 51

Exponential Probability Distribution

Question 52

An entity on which data are collected.

Answer 52

Element

Question 53

A collection of all the elements of interest.

Answer 53

Population

Question 54

A subset of the population.

Answer 54

Sample

Question 55

The population from which the sample is drawn.

Answer 55

Sampled Population

Question 56

A list of the elements from which the sample will be selected.

Answer 56

Frame

Question 57

Some examples of ________ populations are: organization membership rosters, credit card account numbers, inventory product numbers, etc.

Answer 57

Finite

Question 58

Some examples of _______ populations are: parts being manufactured on a production line, transactions occurring at a bank, telephone calls arriving at a technical help desk, etc.

Answer 58

Infinite

Question 59

A form of statistical inference in which data from the sample are used to compute a value of a sample statistic that serves as an estimate of a population parameter.

Answer 59

Point Estimation

Question 60

_____ is the point estimator of the population mean μ.

Answer 60

X Bar

Question 61

_____ is the point estimator of the population standard deviation σ.

Answer 61

S

Question 62

_____ is the point estimator of the population proportion p.

Answer 62

P Bar

Question 63

The population about which we want to make inferences.

Answer 63

Target Population

Question 64

The population from which the sample is actually taken.

Answer 64

Sampled Population

Question 65

The probability distribution of all possible values of the sample mean x bar.

Answer 65

Sampling Distribution of X Bar

Question 66

E(x bar) = ?

Answer 66

Population Mean μ

Question 67

When the sample size is increased, the standard error of the sample mean is increased / decreased.

Answer 67

Decrease

Question 68

The probability distribution of all possible values of the sample proportion p bar.

Answer 68

Sampling Distribution of P Bar

Question 69

E(p bar) = ?

Answer 69

Population Proportion p

Question 70

In stratified random sampling, the best results are obtained when the elements in one stratum form a heterogeneous / homogeneous group.

Answer 70

Homogeneous

Question 71

In cluster sampling, ideally, the elements in each cluster form a heterogeneous / homogeneous group.

Answer 71

Heterogeneous

Question 72

Name 4 probability sampling methods.

Answer 72

Simple Random Stratified Cluster Systemic

Question 73

Name 2 nonprobability sampling method.

Answer 73

Convenience | Judgment