Statistics A Tool for Social Research 10th Edition by Joseph F. – Test Bank

Complete Test Bank With Answers

 

 

Sample Questions Posted Below

 

1.A defining characteristic of the normal curve is that it is

a. theoretical.

b.positively skewed.

c. negatively skewed.

d.perfectly nonsymmetrical.

ANSWER: a

POINTS: 1

REFERENCES: 122

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

2.By definition, the normal curve is

a. symmetrical.

b.positively skewed.

c. negatively skewed.

d.empirical.

ANSWER: a

POINTS: 1

REFERENCES: 122

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

3.The tails of the theoretical normal curve

a. intersect with the horizontal axis between the 4th and 5th standard deviation.

b.intersect with the horizontal axis beyond the 5th standard deviation.

c. never touch the horizontal axis.

d.maintain the same distance above the horizontal axis beyond the 3rd standard deviation.

ANSWER: c

POINTS: 1

REFERENCES: 122

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

4.A common real world application of the normal curve is

a. measuring income levels.

b.assigning exam grades.

c. setting government budgets.

d.None of the above.

ANSWER: b

POINTS: 1

REFERENCES: 122

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.5.In the normal curve, the mean is

a. greater than the median.

b.greater than the mode.

c. less than the median.

d.equal to the median and mode.

ANSWER: d

POINTS: 1

REFERENCES: 122

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

6.In terms of construction, the normal curve is what kind of chart?

a. pie chart.

b.line chart.

c. histogram.

d.bar chart.

ANSWER: b

POINTS: 1

REFERENCES: 122

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

7.Unlike empirical distribution, the theoretical normal curve is

a. positively skewed.

b.negatively skewed.

c. bimodal.

d.perfectly symmetrical.

ANSWER: d

POINTS: 1

REFERENCES: 122

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

8.Distributions of IQ scores are normally distributed because

a. the underlying quality being tested – intelligence – is normally distributed.

b.IQ tests are designed to produce in normal distributions.

c. there is no cultural bias in the tests.

d.they reflect the natural distribution of intelligence: human beings are genetically programmed to have an

average intelligence of about 100.

ANSWER: b

POINTS: 1

REFERENCES: 123

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.9.On all normal curves the area between the mean and ± 1 standard deviation will be

a. about 34% of the total area.

b.about 68% of the total area.

c. 50% of the total area.

d.99.9% of the total area.

ANSWER: b

POINTS: 1

REFERENCES: 124

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

10.On all normal curves the area between the mean and ± 2 standard deviations will be

a. about 34% of the total area.

b.about 95% of the total area.

c. less than 50% of the total area.

d.about 68% of the total area.

ANSWER: b

POINTS: 1

REFERENCES: 124

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

11.On all normal curves the area between the mean and +1 standard deviation will be

a. about 34% of the total area.

b.about 68% of the total area.

c. about 95% of the total area.

d.about 99% of the total area.

ANSWER: a

POINTS: 1

REFERENCES: 124

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.

12.As the standard deviation of a normal distribution increases, the percentage of the area between ± 1 standard

deviation will

a. increase.

b.stay the same.

c. decrease.

d.become non-symmetrical.

ANSWER: b

POINTS: 1

REFERENCES: 124

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.13.The area beyond ± 2 standard deviations contains approximately what % of the area under the normal curve?

a. 75%

b. 50%

c. 99%

d. 5%

ANSWER: d

POINTS: 1

REFERENCES: 124

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

14.Assuming a normal distribution of 1000 cases, how many cases will be farther away from the mean than + 3

standard deviations?

a. At least 500

b.About 3

c. 327

d. It is impossible to estimate

ANSWER: b

POINTS: 1

REFERENCES: 125

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

15.Assuming a normal distribution of 1000 cases, how many cases will be within ± 1 standard deviations of the mean?

a. At least 500

b.About 3

c. About 680

d.It is impossible to estimate

ANSWER: c

POINTS: 1

REFERENCES: 125

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

16.If a case has a Z score of 2.3, the standard deviation would be

a. 4.6

b.1

c.0

d.cannot calculate based on this information.

ANSWER: b

POINTS: 1

REFERENCES: 125

LEARNING OBJECTIVES: STAT.HEAL.15.05.01 – Define and explain the concept of the normal curve.17.Converting scores into Z scores standardizes the original distribution to units of the

a. median.

b.standard deviation.

c. mean.

d.percentage.

ANSWER: b

POINTS: 1

REFERENCES: 126

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

18.The standardized normal distribution (or Z distribution) has

a. a mean of 0 and a standard deviation of 1.

b.a mean of 1 and a standard deviation of 0.

c. a mean equal to the average of the scores and a standard deviation equal to the mean.

d.a mean of 1 and a standard deviation of 1.

ANSWER: a

POINTS: 1

REFERENCES: 126

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

19.When an empirical normal distribution of scores is standardized

a. the mean will become 0.

b.the standard deviation will become 1.

c. each score will be converted to a Z score.

d.All of the above.

ANSWER: d

POINTS: 1

REFERENCES: 126

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

20.If a Z score is 0, then the value of the corresponding raw score would be

a. 0.

b.the same as the mean of the empirical distribution.

c. the same as the standard deviation of the empirical distribution.

d.probably a negative number.

ANSWER: b

POINTS:

1

REFERENCES:

126

LEARNING OBJECTIVES:

STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.21.If a Z score is + 1.00, then the value of the corresponding raw score would be

a. 0.

b.the same as the mean of the empirical distribution.

c. equal to the mean of the empirical distribution plus one standard deviation.

d.probably a negative number.

ANSWER: c

POINTS: 1

REFERENCES: 126

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

22.The Z score table gives the area between a score and the mean. For a Z score of -1.00, that area (in percentages) is

a. 34.13%

b. -34.13%

c. 68.26%

d. -68.26%

ANSWER: a

POINTS: 1

REFERENCES: 127

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

23.A Z score of -2.00 indicates a score that lies

a. two standard deviation units to the right of the mean.

b.two standard deviation units to the left of the mean.

c. 0.5 of one standard deviation unit on each side of the mean.

d.Any of the above are possible, depending on the value of the mean.

ANSWER: b

POINTS: 1

REFERENCES: 127

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

24.A Z score of +1.00 indicates a score that lies

a. one standard deviation unit to the right of the mean.

b.one standard deviation unit to the left of the mean.

c. 1/2 of one standard deviation unit on each side of the mean.

d.Any of the above are possible.

ANSWER: a

POINTS:

1

REFERENCES:

127

LEARNING OBJECTIVES:

STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.25.Column c in the normal curve table lists “areas beyond Z”. This is the area

a. below a positive Z score.

b.above a negative Z score.

c. between two positive Z scores.

d.above a positive Z score.

ANSWER: d

POINTS: 1

REFERENCES: 127

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

26.In a distribution of 150 test scores, the mean grade was an 82 and the standard deviation was 8. If a student scored

a 93, what would their equivalent Z score be?

a. 1.13

b. 1.38

c. 0.68

d. 1.38

ANSWER: d

POINTS: 1

REFERENCES: 127

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

27.The area between the mean and a Z score of +1.50 is 43.32%. This score is higher than in the distribution.

of the scores

a. 43.32%

b. 51.50%

c. 57.68%

d. 93.32%

ANSWER: d

POINTS: 1

REFERENCES: 128-130

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.28.The area between the mean and a Z score of +1.50 is 43.32%. This score is less than the distribution.

of the scores in

a. 43.32%

b. 6.68%

c. 3.32%

d. 93.32%

ANSWER: b

POINTS: 1

REFERENCES: 128-130

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

29.The mean score on a final chemistry exam was 75, and the standard deviation of the scores was 5. If the distribution

is normal and your score was 70, what percentage of the scores was lower than yours?

a. 15.87%

b. 30.00%

c. 34.13%

d. 50.00%

ANSWER: a

POINTS: 1

REFERENCES: 128-130

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

30.The mean on a standardized test is 100 and the standard deviation is 35. Your score is 65. What percentage of the

scores were higher than yours?

a. About 84%

b.No more than 50%

c. About 34%

d.About 16%

ANSWER: a

POINTS: 1

REFERENCES: 128-130

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.31.To find the area above a positive Z score or below a negative Z score you would

a. subtract the value of the Z score from the mean.

b.use the “Area Beyond Z” column of the Z score table.

c. add the value of the Z score to the area beyond the mean.

d.add the area between the Z score and the mean to 100%.

ANSWER: b

POINTS: 1

REFERENCES: 128-129

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

32.To obtain the area below a positive Z score or above a negative Z score you would

a. subtract the value of the Z score from the mean.

b.subtract the area in the “Area Beyond Z” column of the Z score table from 50%.

c. add the value of the Z score to the area beyond the mean.

d.add the area between the Z score and the mean to 50%.

ANSWER: d

POINTS: 1

REFERENCES: 128-129

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

33.As used in the social sciences, probabilities are a type of a. percentage, 0 to 1

b.fraction, 0 to 100

c. proportion, 0.00 to 1.00

d.Z score, 0 to infinity

which can vary from .

ANSWER: c

POINTS: 1

REFERENCES: 130

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.34.The Z scores of two tests scores are + 1.2 and + 1.5. To obtain the area between these scores

a. subtract the Z scores and find the area of the difference in the Z score table.

b.find the area between each score and the mean in the Z score table and then subtract the smaller area from

the larger area.

c. find the area between each score and the mean in the Z score table and then subtract the difference between

them from 100%.

d.find the area beyond each score in the Z score table and subtract the difference between the areas from the

mean.

ANSWER: b

POINTS: 1

REFERENCES: 131-132

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

35.The area between a negative Z score and a positive Z score can be found by

a. subtracting the Z scores from each other.

b.subtracting each Z score from the mean and adding the results.

c. adding the Z scores and finding the area in the Z score table for the summed Z scores.

d.adding the areas between each Z score and the mean.

ANSWER: d

POINTS: 1

REFERENCES: 131-132

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

36.The Z scores of two test scores are – 1.17 and + 2.38. To find the total area between these two scores

a. add the column b areas together.

b.subtract each score from the mean and divide the result by the standard deviation.

c. add the column b area to the column c area.

d.add the column c areas.

ANSWER: d

POINTS: 1

REFERENCES: 131-132

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.37.The area between two negative Z scores can be found by

a. adding the Z scores and finding the area below the total Z score.

b.subtracting the Z scores and finding the total area above the total Z score.

c. finding the area between each Z score and the mean and subtracting the smaller area from the larger.

d.finding the area between each Z score and the mean and adding the areas.

ANSWER: c

POINTS: 1

REFERENCES: 131-132

LEARNING OBJECTIVES: STAT.HEAL.15.05.02 – Convert empirical scores to Z scores and use Z scores and

the normal curve to find areas above, below, and between points on the curve.

38.To estimate probabilities, set up a fraction with the number of in the denominator.

a. successes, failures

b.possible outcomes, successes

c. failures, successes

d.successes, possible outcomes

in the numerator and the number of

ANSWER: d

POINTS: 1

REFERENCES: 134

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.

39.The probability of getting a 1 in a single toss of a six sided die would be

a. 2 to 1.

b.60 to 1.

c. 1 in 6.

d.impossible to estimate with the information given.

ANSWER: c

POINTS: 1

REFERENCES: 134

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.

40.If a case is randomly selected from a normal distribution, the score of the case will most likely be

a. equal to the mean in value.

b.close to the mean in value.

c. at least 1 standard deviation above the mean.

d.at least 1 standard deviation below the mean.

ANSWER: b

POINTS: 1

REFERENCES: 135

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.41.The probability that a randomly selected case will have a score beyond ± 1.00 standard deviation of the mean is

a. 0.6826.

b. 0.5000.

c. 0.3174.

d. 1/2 of the area of 1 standard deviation.

ANSWER: c

POINTS: 1

REFERENCES: 135

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.

42.A social researcher has constructed a measure of racial prejudice and obtained a distribution of scores on this

measure from a randomly selected sample of public office holders. The scores were normally distributed with a

mean of 45 and a standard deviation of 7. What is the probability that a randomly selected case from the sample will

have a score less than 38?

a. 0.4526

b. 0.5018

c. 0.5200

d. 0.1587

ANSWER: d

POINTS: 1

REFERENCES: 135

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.

43.What is the probability that a randomly selected case from the sample in the previous question would have a score of

52 or more?

a. 0.7500

b. 0.6826

c. 0.3413

d. 0.1587

ANSWER: d

POINTS: 1

REFERENCES: 135

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.

44.What is the probability that a randomly selected case from a normally distributed distribution will have a score

between -1.00 and the mean?

a. 0.34

b. 0.16

c. 0.50

d. 0.86

ANSWER: a

POINTS: 1

REFERENCES: 135

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.45.The average homicide rate for the cities and towns in a state is 10 per 100,000 population with a standard deviation

of 2. If the variable is normally distributed, what is the probability that a randomly selected town will have a homicide

rate greater than 14?

a. 0.34

b. 0.68

c. 0.50

d. 0.02

ANSWER: d

POINTS: 1

REFERENCES: 135

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.

46.The average homicide rate for the cities and towns in a state is 10 per 100,000 population with a standard deviation

of 2. If the variable is normally distributed, what is the probability that a randomly selected town will have a homicide

rate greater than 8?

a. 0.34

b. 0.68

c. 0.84

d. 0.01

ANSWER: c

POINTS: 1

REFERENCES: 135

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.

47.The text discusses an application of probability theory that involved

a. betting on horse races.

b.casino gambling.

c. cheating on final exams.

d.betting on the outcome of the presidential election.

ANSWER: b

POINTS: 1

REFERENCES: 137

LEARNING OBJECTIVES: STAT.HEAL.15.05.03 – Express areas under the curve in terms of probabilities.48.A sample of university students has an average GPA of 2.78 with a standard deviation of 0.45. If GPA is normally

distributed, what percentage of the students has GPAs

Z score Area

a. less than 2.30

b. less than 2.00

c. more than 2.00

d. more than 3.00

e. between 2.50 and 3.50

f. between 2.00 and 2.50

ANSWER:

Z score Area

a. -1.07 14.23%

b. -1.73 4.18%

c. -1.73 95.82%

d. 0.49 31.21%

e. -0.62 and 1.60 67.76%

f. -1.73 and -0.62 22.58%

POINTS: 1

49.For the distribution of GPAs described in problem 1, what is the probability that a randomly selected student will

have a GPA

Z score Probability

a. less than 3.40

b. less than 3.78

c. more than 3.50

d. more than 2.50

e. between 2.00 and 3.00

f. between 3.00 and 3.50

ANSWER:

Z score Area

a. 1.38 0.92

b. 2.22 0.99

c. 1.60 0.06

d. -0.62 0.73

e. -1.73 and 0.49 0.65

f. 0.49 and 1.60 0.26

POINTS: 1