Question 1

As used in the social sciences, probabilities are a type of ___________ which vary from _____________ .

Accepted Answer

A)   percentage, 0 to 1
B)   fraction, 0 to 100
C)   proportion, 0.00 to 1.00
D)   Z score, 0 to infinityE) B) and D)
F) B) and C)

Question 2

Unlike empirical distribution, the theoretical normal curve is

Accepted Answer

A)   positively skewed
B)   negatively skewed
C)   bimodal
D)   perfectly symmetricalE) A) and D)
F) None of the above

Question 3

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?

Accepted Answer

A)   15.87%
B)   30.00%
C)   34.13%
D)   50.00%E) A) and D)
F) B) and D)

Question 4

A Z score of +1.00 indicates a score that lies

Accepted Answer

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 possibleE) A) and B)
F) B) and C)

Question 5

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?

Accepted Answer

A)   0.34
B)   0.68
C)   0.84
D)   0.01E) All of the above
F) C) and D)

Question 6

Column c in the normal curve table lists "areas beyond Z". This is the area

Accepted Answer

A)   below a positive Z score
B)   above a negative Z score
C)   between two positive Z scores
D)   above a positive Z scoreE) All of the above
F) A) and C)

Question 7

The tails of the theoretical normal curve

Accepted Answer

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)   extend infinitely in both directions
D)   maintain the same distance above the horizontal axis beyond the 3rd standard deviationE) C) and D)
F) B) and D)

Question 8

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

Accepted Answer

A)   2 to 1
B)   60 to 1
C)   1 in 6
D)   impossible to estimate with the information givenE) All of the above
F) B) and D)

Question 9

Converting scores into Z scores standardizes the original distribution to units of the

Accepted Answer

A)   median
B)   standard deviation
C)   mean
D)   percentageE) None of the above
F) C) and D) B

Question 10

What is the probability that a randomly selected case from the sample in the previous question would have a score of 52 or more?

Accepted Answer

A)   0.7500
B)   0.6826
C)   0.3413
D)   0.1587E) A) and D)
F) A) and B)

Question 11

When an empirical normal distribution of scores is standardized

Accepted Answer

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 aboveE) B) and C)
F) A) and B) D

Question 12

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

Accepted Answer

A)   34.13%
B)   -34.13%
C)   68.26%
D)   -68.26%E) A) and D)
F) C) and D)

Question 13

Distributions of IQ scores are normally distributed because

Accepted Answer

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.E) C) and D)
F) None of the above

Question 14

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

Accepted Answer

A)   increase
B)   stay the same
C)   decrease
D)   become non-symmetricalE) B) and C)
F) C) and D) B

Question 15

To estimate probabilities, set up a fraction with the number of _________ in the numerator and the number of _________ in the denominator

Accepted Answer

A)   successes, failures
B)   possible outcomes, successes
C)   failures, successes
D)   successes, possible outcomesE) A) and D)
F) B) and D)

Question 16

For a normal distribution of 1000 cases, how many cases will be farther away from the mean than ± 3 standard deviations?

Accepted Answer

A)   at least 500
B)   about 3
C)   327
D)   it's impossible to estimateE) A) and D)
F) B) and D)

Question 17

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?

Accepted Answer

A)   0.34
B)   0.68
C)   0.50
D)   0.02E) C) and D)
F) A) and D)

Question 18

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

Accepted Answer

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 meanE) A) and B)
F) All of the above

Question 19

The area between two negative Z scores can be found by

Accepted Answer

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 areasE) B) and D)
F) B) and C)

Question 20

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?

Accepted Answer

A)   about 84%
B)   no more than 50%
C)   about 34%
D)   about 16%E) None of the above
F) All of the above

Exam 5: The Normal Curve

As used in the social sciences, probabilities are a type of ___________ which vary from _____________ .

Correct AnswerverifiedShow Answer

Unlike empirical distribution, the theoretical normal curve is

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

A Z score of +1.00 indicates a score that lies

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

Column c in the normal curve table lists "areas beyond Z". This is the area

Correct AnswerverifiedShow Answer

The tails of the theoretical normal curve

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Converting scores into Z scores standardizes the original distribution to units of the

Correct AnswerverifiedB

What is the probability that a randomly selected case from the sample in the previous question would have a score of 52 or more?

Correct AnswerverifiedShow Answer

When an empirical normal distribution of scores is standardized

Correct AnswerverifiedD

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

Correct AnswerverifiedShow Answer

Distributions of IQ scores are normally distributed because

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedB

To estimate probabilities, set up a fraction with the number of _________ in the numerator and the number of _________ in the denominator

Correct AnswerverifiedShow Answer

For a normal distribution of 1000 cases, how many cases will be farther away from the mean than ± 3 standard deviations?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The area between two negative Z scores can be found by

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

As used in the social sciences, probabilities are a type of _ which vary from ___ .

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

Correct Answer
verified

Correct Answer
verified
D

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
B

To estimate probabilities, set up a fraction with the number of _ in the numerator and the number of _ in the denominator

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified