Deck 10: Probability and Sampling Distributions

Question 1

The term parameter

A)Applies only to sample statistics.
B)Is synonymous with the term perimeter.
C)Is used instead of the term statistic when referring to a summary statistic for an entire population.
D)Can be used interchangeably with the term statistic regardless of whether we are referring to a sample or a population.

Answer 1

Is used instead of the term statistic when referring to a summary statistic for an entire population.

Question 2

Inferential statistics can be used to generalize from sample statistics to population parameters.

Answer 2

True

Question 3

The term chance:

A)Refers to sampling errors that result from biased sampling procedures.
B)Refers to sampling errors that inevitably occur in random sampling.
C)Refers to errors that are avoided when random sampling is used.
D)None of these are true.

Answer 3

Refers to sampling errors that inevitably occur in random sampling.

Question 4

As sample size increases:

A)The probability of flukes in random selection or random assignment increases.
B)The probability of flukes in random selection or random assignment decreases.
C)Sampling error increases.
D)Sampling error is unaffected

Question 5

If the sample size is 4000, and the standard deviation of the sample is 200, then the standard error is:

A)1
B)20
C)200
D)2

Question 6

The standard error:

A)Equals the standard deviation of the sample divided by the square root of the sample size.
B)Equals the standard deviation of the population divided by the standard deviation of the sample.
C)Equals the standard deviation of the sample multiplied by the square root of the sample size.
D)Equals the standard deviation of the sample divided by the sample size.

Question 7

The probability of a particular outcome occurring is equal to:

A)The number of ways that particular outcome can occur divided by the total number of all possible outcomes.
B)The total number of all possible outcomes divided by the number of ways that particular outcome can occur.
C)The number of ways that particular outcome can occur multiplied by the number of ways that particular outcome can occur.
D)The total number of all possible outcomes minus the number of ways that particular outcome can occur.

Question 8

The probability that two particular outcomes will occur is determined by:

A)Adding one outcome's probability to the other outcome's probability.
B)Subtracting one outcome's probability from the other outcome's probability.
C)Multiplying one outcome's probability by the other outcome's probability.
D)Dividing one outcome's probability by the other outcome's probability.

Question 9

According to the central limit theorem:

A)As the size of the sample increases, the theoretical sampling distribution based on that sample size will become more skewed.
B)As the size of the sample increases, its mean will become increasingly closer to the population mean.
C)As the size of the sample increases, its mean will become farther away from the population mean
D)None of these are correct.

Question 10

If the probability that Jack will be assigned to the experimental group is .50, and the probability that Jill will be assigned to the experimental group is also .50, then the probability that both Jack and Jill will be assigned to the experimental group is .50.

Question 11

Suppose you flipped a coin three times.The probability of getting three heads would be:

A).167
B)125.
C)½ times 1/3 times 1/4
D)½ times ¼ times 1/8

Question 12

Suppose a client satisfaction survey is conducted of all of the service recipients in Agency A.If all of the recipients participate in the survey, and if the survey seeks to describe client satisfaction in Agency A, only, with no intent to generalize about service recipients elsewhere, then for this study the survey participants comprise a:

A)Population.
B)Sample.
C)Both a population and a sample
D)Neither a population nor a sample

Question 13

If your caseload is comprised of 10 clients, and your agency's total caseload contains 100 clients, and your agency director chooses one client at random to serve as a consumer representative on your agency's board, then the probability that one of your clients will be chosen is.05.

Question 14

Inferential statistics:

A)Are limited to descriptively summarizing a study's data.
B)Pertain to a study's sample, only, and not to any larger population.
C)Can be used to assess the probability that differences between groups can be attributed to sampling error.
D)Assess the likelihood that two groups are equivalent.

Question 15

As sample size increases, the probability of flukes in random selection or random assignment increases.

Question 16

Suppose your agency serves 100 clients, and 40 of them are African Americans.The probability of selecting two African Americans on your first two random picks would be:

A).16.
B).20
C).40 times 39/99
D).80

Question 17

The term parameter is used instead of statistic when referring to a summary statistic for an entire population.

Question 18

The term chance refers to sampling errors that inevitably occur in random sampling.

Question 19

In a 95 percent confidence interval:

A)The 95 percent is the confidence level.
B)Shows that there is a 95 percent probability that the true population mean falls somewhere between plus and minus 1.96 standard errors of the sample mean.
C)There is a .05 probability of the confidence interval being wrong.
D)All of these.

Question 20

Suppose a survey is conducted of all of the licensed therapists in Illinois regarding their attitudes about evidence-based practice.If the survey seeks to generalize about therapists' attitudes nationwide, then for this study the survey participants comprise a:

A)Population.
B)Sample.
C)Both a population and a sample
D)Neither a population nor a sample

Question 21

Theoretical sampling distributions only rarely approximate normal curves.

Question 22

If the sample mean equals 100, and the standard error equals 5, then we can be 95 percent confident that the population mean falls somewhere between 95 and 105.

Question 23

The standard error equals the standard deviation of the sample divided by the square root of the sample size.

Question 24

Theoretical sampling distributions enable us to estimate our likely degree of sampling error.