Deck 7: Understanding Data: Using Statistics for Inference and Estimation

Question 1

Representativeness of a sample is principally determined by the.

A)method of sampling used
B)size of the sample
C)symmetry of the population distribution
D)standard error of the mean

Answer 1

A

Question 2

If an estimator is consistent, more accurate estimates of population parameters will be obtained from samples that are.

A)smaller
B)symmetrical
C)unimodal
D)larger

Answer 2

D

Question 3

A sample statistic may be used to estimate a.

A)population statistic
B)population parameter
C)sample mean
D)sample parameter

Answer 3

B

Question 4

In simple random sampling,.

A)the members of the population do not know each other
B)the selection of one member of the population does not affect the probability of selection of another member
C)each member of the population must volunteer for the sample
D)each member of the population must be informed about being selected

Question 5

A population parameter is estimated by a.

A)population statistic
B)population stratum
C)sample statistic
D)sample parameter

Question 6

Suppose you have a statistic such that, as the sample size becomes larger, the probability that the statistic comes closer to the parameter it estimates does not increase. This statistic is estimator.

A)not a consistent
B)a biased
C)an unbiased
D)a consistent

Question 7

A(n) estimator is one for which the probability that its value is close to the value of the parameter increases as the sample size increases.

A)unbiased
B)consistent
C)biased
D)inconsistent

Question 8

To obtain accurate estimates of a parameter, a sample should be.

A)inconsistent
B)representative of the population
C)simply selected
D)non-representative of the population

Question 9

Statistical inference is the process of estimating population parameters from sample statistics.

A)known; known
B)known; unknown
C)unknown; unknown
D)unknown; known

Question 10

A researcher can expect to obtain more accurate estimates of population parameters with random samples from populations in which the variability in scores to be sampled is .

A)large; large
B)small; small
C)large; small
D)small; large

Question 11

The the sample size and the the variability of scores, the more accurately a sample mean will estimate a population mean.

A)smaller; larger
B)larger; smaller
C)smaller; smaller
D)larger; larger

Question 12

For a consistent estimator, which of the following sample sizes would yield the most accurate estimate of a population parameter?

A)5
B)24
C)30
D)68

Question 13

In simple random sampling,.

A)the members of the population do not know each other
B)each member of the population must volunteer for the sample
C)each member of the population must be informed about being selected
D)each member of the population has an equal chance of being selected

Question 14

The scores vary in the population and the the sample size, then the more accurately a sample mean will estimate a population mean.

A)less; larger
B)less; smaller
C)more; larger
D)more; smaller

Question 15

If each member of a population has an equal chance of being selected for a sample and the selection of one member of the population is independent of the selection of another member, then the method of sampling is sampling.

A)stratified random
B)diversified non-random
C)simple random
D)consistent random

Question 16

If a statistic is consistently larger than the parameter it estimates, then the statistic is a(n) estimator.

A)unbiased
B)consistent
C)inconsistent
D)biased

Question 17

A(n) estimator is a statistic for which, if an infinite number of random samples of a certain size were obtained, the mean of the values of the statistic would equal the parameter being estimated.

A)interval
B)point
C)unbiased
D)consistent

Question 18

Using a statistic to estimate a parameter as a single value is called estimation.

A)interval
B)point
C)unbiased
D)consistent

Question 19

As the sample size increases the probability increases that the population parameter is more closely estimated by the statistic; thus, the estimator is.

A)unbiased
B)biased
C)consistent
D)inconsistent

Question 20

The value of

A)is an unbiased estimator
B)overestimates the value
C)underestimates the value
D)is an interval estimate

Question 21

In a sampling distribution of the mean, approximately percent of the sample means will be contained within the interval of two standard errors above and below the population mean.

A)34
B)68
C)95
D)over 99

Question 22

A population has a mean of 50 and a standard deviation of 8. If samples of size N = 16 are randomly drawn from this population, then the standard error will be equal to.

A)1.0
B)2.0
C)8.0
D)0.5

Question 23

Which of the following considerations influences how well a statistic estimates a parameter?

A)The sampling method used.
B)The size of the sample.
C)The variability of scores in the population.
D)All the above.

Question 24

The value of is used to estimate σ.

A)
B)s

Question 25

The sampling distribution of the mean is.

A)a theoretical distribution
B)the best estimate for the range of population means
C)likely to be skewed
D)useful only when the sampling is not random

Question 26

A sampling distribution of the mean can be described in terms of its.

A)shape
B)mean
C)standard deviation
D)all the above

Question 27

If the sample mean has the same value as the population mean, then for that sample mean the.

A)sampling error is zero
B)sampling error is 1.0
C)sampling error is greater than zero, but less than 1.0
D)sample mean must be incorrect

Question 28

A population has a mean of 100 and a standard deviation of 5. If samples of size N = 25 are randomly drawn from this population, then the standard error will be equal to.

A)1.0
B)5.0
C)0.2
D)0.5

Question 29

The distribution of X values when all possible samples of size N are selected from a population is called a distribution of the mean.

A)simple
B)relative frequency
C)sampling
D)normal

Question 30

A theoretical probability distribution of values of a statistic resulting from selecting all possible samples of size N from a population is called a distribution of that statistic.

A)simple
B)sampling
C)relative frequency
D)normal

Question 31

As sample size increases, a sampling distribution of the mean will approximate a normal distribution, regardless of the shape of the distribution of scores in the population. This characteristic of the sampling distribution of the mean is stated in the.

A)principle of normalcy
B)principle of empiricism
C)central limit theorem
D)independence theorem

Question 32

A frequency distribution of sample means obtained by actually selecting samples from a population and then computing the means of those samples is called a(n) sampling distribution of the mean.

A)random
B)empirical
C)theoretical
D)actual

Question 33

Which of the following statements is correct?

A)The smaller the sample, the smaller the sampling error.
B)The smaller the sample, the more consistent the sampling error.
C)The larger the sampling error, the more consistent the estimate.
D)The larger the sample, the smaller the sampling error.

Question 34

For population distributions that are not heavily skewed, many statisticians consider a minimum sample size of to produce a sampling distribution of the mean that will approximate a normal distribution.

A)5
B)8
C)30
D)36

Question 35

The standard error is the.

A)average deviation of the sample means subtracted from the population mean
B)maximum amount by which individual scores vary around the sample mean
C)standard deviation of the sampling distribution of the mean
D)mean sampling error divided by the sample size

Question 36

Sampling error refers to.

Question 37

The central limit theorem indicates that as sample size increases, the theoretical sampling distribution of the mean.

A)becomes bimodal
B)becomes less normally distributed
C)becomes asymmetrical
D)approaches a normal distribution

Question 38

A standard error of the mean is a standard deviation of a.

A)population
B)sample
C)population parameter
D)sampling distribution of the mean

Question 39

The error in estimating a population mean from a sample mean is called error.

A)sampling
B)random
C)chance
D)distribution

Question 40

The theoretical sampling distribution of the mean.

A)is symmetrical
B)is unimodal
C)approximates a normal distribution
D)all the above

Question 41

Which of the following statements is true?

A)The larger the sample size, the larger the variance.
B)The higher the confidence level, the smaller the confidence interval.
C)The smaller the sample size, the smaller the confidence interval.
D)The larger the sample size, the smaller the standard error.

Question 42

If s=14 and N=49 , then

A)
B) 0.5
C) 2.00
D)

Question 43

A population has a mean of 100 and a standard deviation of 15. If samples of size N = 25 are randomly drawn from this population, then what proportion of sample means will fall between 97 to 103?

A).6826
B).3413
C).5000
D).9544

Question 44

The value of s X is affected by the size of the sample and the.

A)mean of scores in the sample
B)mean of the population
C)variance of the population
D)shape of the frequency distribution

Question 45

The the variation in the population and the the sample size, then the larger the estimated standard error.

A)less; larger
B)more; larger
C)more; smaller
D)less; smaller

Question 46

If s = 10 and s X = 2, then N must be equal to.

A)20
B)25
C)5
D)cannot determine from the

Question 47

If you wish to increase the confidence level for the estimation of a parameter, then the .

A)confidence interval will get larger
B)confidence interval will get smaller
C)sample must be smaller
D)variance must be increased

Question 48

A 95% confidence interval is determined by the interval of plus or minus standard errors around the mean.

A)1.96; population
B)2.58; population
C)1.96; sample
D)2.58; sample

Question 49

The estimated standard error of the mean, s X

Question 50

The interval from the population mean to one standard error below the mean in a sampling distribution of the mean contains approximately percent of the sample means.

A)14
B)34
C)50
D)68

Question 51

You can be about percent confident that an interval that includes the values between one standard error below the sample mean and one standard error above the sample mean will include the population mean.

A)34
B)68
C)95
D)99

Question 52

The size of s X . is related to the variability of scores in the population and to the sample

A)standard deviation
B)mean
C)variance
D)size

Question 53

An interval in which we can have a specified confidence that the interval includes μ is called a(n).

A)confidence limit
B)estimation interval
C)confidence point
D)confidence interval

Question 54

The lower and upper scores of a confidence interval are called.

A)confidence scores
B)estimation scores
C)confidence points
D)confidence limits

Question 55

You can be percent confident that an interval that includes the values between 1.96 standard errors below the sample mean and 1.96 standard errors above the sample mean will include the population mean.

A)34
B)68
C)95
D)99

Question 56

A population has a mean of 70 and a standard deviation of 8. If samples of size N = 16 are randomly drawn from this population, then what proportion of sample means will fall between 66 to 74?

A).6826
B).3413
C).5000
D).9544

Question 57

A value of X may be converted to a score on the standard normal distribution by using the formula.

Question 58

Which of the following statements is correct?

A)The higher the confidence level, the smaller the confidence interval.
B)The lower the confidence level, the smaller the confidence interval.
C)The greater the population variance, the smaller the confidence interval.
D)None of the above.