Deck 6: Accommodating Student Variability

Question 1

Using inferential statistics, we can learn about the population by studying:

A) reliability of the null hypothesis.
B) Type I errors.
C) the sample.
D) confounds.

Answer 1

C

Question 2

The probability of obtaining three consecutive heads on three tosses of a coin is:

A) 1.50
B) .50
C) .25
D) .125

Answer 2

D

Question 3

The probability of obtaining one head and then followed by one tail on two tosses of a coin is:

A) .25
B) .50
C) .75
D) 1.00

Answer 3

A

Question 4

Which of the following p values gives you the least confidence regarding the outcome of a study?

A) p<.10
B) p<.05
C) p<.01
D) p<.001

Question 5

The probability of obtaining two heads and one tail (in any order) in three tosses of a coin is:

A) .125
B) .375
C) .50
D) 1.50

Question 6

If your results were significant at p<.001:

A) the probability that the results occurred by chance is less than 1 in 1000.
B) the probability of being correct is less than 1 in 1000.
C) the probability that the experimental manipulation worked is less than 1 in 1000.
D) none of these

Question 7

Refer to Scenario 6-1. What is the probability that the student is a psychology major?

A) .40
B) .50
C) .80
D) .95

Question 8

Jason flips a coin one hundred times, and it comes up heads every time. Jason predicts that the next flip of the coin is highly likely to yield tails because that outcome is long overdue. Jason is:

A) not taking into account independent events.
B) affected by the gambler's fallacy.
C) not aware of how probability works.
D) all of these

Question 9

The probability of dealing a spade or a heart from a fair deck of cards is:

A) .125
B) .25
C) .50
D) 1.50

Question 10

Inferential statistics allow us to:

A) infer from a population the characteristics of a sample.
B) infer from a sample the characteristics of a population.
C) infer that a sample is random.
D) describe the statistical properties of a sample.

Question 11

If you commit the gambler's fallacy in games of chance, then you fail to appreciate the fact that:

A) each outcome is independent of previous outcomes.
B) each outcome is dependent on previous outcomes.
C) outcome probabilities change from trial to trial.
D) each outcome is conditional on a prior outcome.

Question 12

Refer to Scenario 6-1. What is the probability that the student is a sociology major?

A) .20
B) .30
C) .40
D) .50

Question 13

If the probability of an event occurring is .70, then the probability of the event not occurring is:

A) 1.00
B) .70
C) .50
D) .30

Question 14

Refer to Scenario 6-1. What is the probability that the student is either a psychology major or sociology major?

A) .10
B) .40
C) .80
D) 1.00

Question 15

The probability of dealing a spade from a fair deck of cards is:

A) .125
B) .25
C) .50
D) 1.50

Question 16

Which of the following p levels gives you the most confidence regarding the outcome of a study?

A) p<.10
B) p<.05
C) p<.01
D) p<.001

Question 17

Refer to Scenario 6-1. What is the probability that the student is male?

A) .20
B) .30
C) .40
D) .50

Question 18

The probability of obtaining either a head or a tail on any coin toss is:

A) 1.00
B) .75
C) .50
D) .25

Question 19

If an experimental report states that results are significant p<.05, this means that if the experiment was repeated you would expect:

A) to obtain the same result less than 5 times in 100.
B) the result to occur by chance less than 95 times in 100.
C) the result to occur by chance less than 5 times in 100.
D) to obtain the same result more than 55 times.

Question 20

Sample is to population as ____ is to ____.

A) statistic; parameter
B) inductive; deduction
C) parameter; variance
D) Type I; Type II

Question 21

If many large samples are drawn from a population and their means plotted, the variability of those means will be ____ than if many small samples are drawn.

A) smaller
B) larger
C) no different
D) either larger or no different

Question 22

To compare the means of two randomly assigned groups of individuals, the appropriate test is:

A) a t-test for dependent groups.
B) a t-test for matched scores.
C) a t-test for independent groups.
D) any one of these

Question 23

Suppose that height is a normally distributed variable with mean of 66 inches and a standard deviation of 3 inches. If you select a person at random from the population, what is the probability that the person is between 60 and 72 inches tall?

A) .34
B) .475
C) .68
D) .95

Question 24

In the normal distribution, the percentage of scores that fall within one standard deviation of the mean is approximately:

A) 34%
B) 50%
C) 68%
D) 95%

Question 25

In the normal distribution, the percentage of scores than fall within two standard deviations of the mean is approximately:

A) 34%
B) 50%
C) 68%
D) 95%

Question 26

The standard deviation of the sampling distribution of the means is called the:

A) variance.
B) standard score.
C) standard error.
D) confidence interval.

Question 27

Jane has scored 132 on an IQ test. The mean of all the people who took the same test is 100 and the standard deviation is 16. What percentage of people scored below Jane?

A) 15%
B) 34%
C) 95%
D) 97.5%

Question 28

In general, the null hypothesis means that:

A) subjects were randomly assigned to groups.
B) a confounding variable is responsible for differences between subject groups.
C) subject groups came from the same population.
D) there is a significant difference between subject groups.

Question 29

Suppose that height is a normally distributed variable with mean of 66 inches and a standard deviation of 3 inches. You are 72 inches tall. How many standard deviations are you above the mean?

A) impossible to tell without more information
B) 1
C) 2
D) 3

Question 30

Characteristics of a population are referred to as ____ whereas characteristics of a simple sample are referred to as ____.

A) statistics; parameters
B) parameters; statistics
C) parameters; probabilities
D) probabilities; parameters

Question 31

The hypothesis that the population mean is the same as the sample mean is called the:

A) research hypothesis.
B) null hypothesis.
C) alternative hypothesis.
D) inferential hypothesis.

Question 32

The additive rule of probability is:

A) probability (A or B) = probability (A) + probability (B)/AB.
B) probability (A or B) = (probability (A) + probability (B))/2.
C) probability (A or B) = probability (A) - probability (B).
D) probability (A or B) = probability (A) + probability (B).

Question 33

When using inferential statistics to estimate the population variance, you divide the sum of the squares by:

A) N
B) N+1
C) square root of N
D) N-1

Question 34

If lines are drawn from the points of inflection of the normal curve perpendicular to the x-axis, the x-axis would be divided into segments equal to:

A) .05.
B) the variance.
C) the standard deviation.
D) the confidence interval.

Question 35

Which of the following is incorrect?

A) population mean - $\mu$
B) sample mean - X
C) sample standard deviation - SD
D) population standard deviation - $\sigma$

Question 36

As the sample size increases, standard error:

A) decreases.
B) increases.
C) stays the same.
D) may increase or decrease depending on the size of the population.

Question 37

We describe characteristics of a sample by using italicized ____ letters and characteristics of a population by using ____ letters.

A) Greek; English
B) Roman; English
C) Roman; Greek
D) Greek; Roman

Question 38

The Central Limit theorem states that:

A) if many samples are drawn randomly from a population, their means tend to be normally distributed.
B) the means of large samples will be better measures of central tendency than the means of small samples.
C) most scores will fall within three standard deviations of the mean.
D) the standard error of a distribution is limited by its central tendency.

Question 39

Using inferential statistics, we test hypotheses about:

A) the population.
B) the sample.
C) the relation between the samples.
D) all of these

Question 40

Suppose that height is a normally distributed variable with mean of 66 inches and a standard deviation of 3 inches. About what percentage of people would have a height between 66 and 72 inches?

A) 48%
B) 68%
C) 75%
D) 95%

Question 41

Describe and draw the characteristics of the normal distribution.

Question 42

An analysis of variance is the appropriate test when there are ____ conditions in an experiment.

A) two
B) three
C) four
D) three or more

Question 43

In a journal article, it was reported that t(16) = 3.42, p < .01. What does this mean? Explain each of the components of this mathematical statement.

Question 44

Discuss the gambler's fallacy in the context of independent events.

Question 45

What is the sampling distribution of the mean? What is its purpose in inferential statistics? How does sample size affect the properties of this distribution?

Question 46

You read that the results of a t-test was t(12) = 3.98, p >.01. What does this mean?

A) The t value is 12, the degrees of freedom is 3.98, and the result would occur by chance fewer than 1 in 100 times.
B) The t value is 3.98, the degrees of freedom is 12, and the results would occur by chance fewer than 1 in 100 times.
C) The t value is .01, the degrees of freedom is 12, and the results would occur by chance fewer than 3.98 in 100 times.
D) The t value is .01, the degrees of freedom is 3.98, and the results would occur by chance fewer than 12 in 100 times.

Question 47

What does the t-test reveal about sample means?

Question 48

The sample standard deviation is symbolized by ____.

A) df
B) $\sigma$
C) S
D) S²

Question 49

Discuss the Central Limit Theorem and its use in inferential statistics.

Question 50

If your study involves more than two groups, ____ would be more appropriate than ____ to reveal differences.

A) analysis of variance; t-test
B) t-test; analysis of variance
C) analysis of variance; r
D) r; t-test

Question 51

What are inferential statistics and what is being inferred?

Question 52

One-tailed test is a ____ test, while a two-tailed test is a ____ test.

A) unidirectional; bidirectional
B) parametric; statistical
C) unidirectional; multidirectional
D) nominal; ordinal

Question 53

Compare and contrast t-tests with analysis of variance.

Question 54

What is the null hypothesis? What does it mean to reject the null hypothesis? Why and how is this an inferential process?

Question 55

What does p < .001 mean and how is it used in t-tests?

Question 56

If you hypothesized that the experimental group would perform better that the control group, the statistical test is:

A) bidirectional.
B) one-tailed.
C) two-tailed.
D) significant.

Question 57

What are the advantages and disadvantages of using a one-tailed t-test?

Question 58

What term refers to the number of scores that are free to vary?

A) sum of squares
B) N
C) degrees of freedom
D) variance

Question 59

Which of the following best describes the relationship between t-test and analysis of variance?

A) t²=r²
B) F= $\sigma$
C) t² = p <.001
D) F=t²

Question 60

What is meant by statistical significance? Relate this concept to probability theory.