Question 1

What do z-scores represent?

Accepted Answer

Z-scores represent the value of a particular case relative to the mean, measured in units of standard deviation. In other words, a z-score is the number of standard deviations between a case and the mean.

Question 2

Relative frequency refers to the proportion of times that we observe an event occurring.

Accepted Answer

A) True 
 B)False  False

Question 3

When calculating the probability of pulling one of ten names out of a hat, the denominator is the 	-------------.

Accepted Answer

A)   number of attempts
B)   number of names
C)   number of attempts multiplied by number of names
D)   number of attempts divided by number of names B

Question 4

Drawing a card from a deck, returning it, and then determining the probability of drawing the same card is an example of probability without replacement.

Accepted Answer

A) True 
 B)False

Question 5

Use the following table to answer questions:
RACE OF RESPONDENT
 
-What is the probability of consecutively selecting two white respondents?

Accepted Answer

A)   .02
B)   .27
C)   .53
D)   .73

Question 6

The 2006 GSS asked respondents how many siblings they have. The mean number of siblings was 3.76 with a standard deviation of 3.178. Use this information to answer the following questions: a. What number of siblings falls at the 50^th percentile? b.What is the z-score associated with a raw score of 2 siblings? c.What is the z-score associated with a raw score of 6 siblings? d.What is the probability of selecting arespondent with more than 10 siblings? e.What is the probability of selecting eithera respondent with 2 or fewer siblings, or arespondent with more than 5? f.What is the probability of a respondent having between 2 and 5 siblings?

Accepted Answer

The answer of The 2006 GSS asked respondents how many...

Question 7

Use the following table to answer questions:
RACE OF RESPONDENT
 
-What is the probability of selecting a respondent who is black?

Accepted Answer

A)   .13
B)   .14
C)   .27
D)   .73

Question 8

Use the following table to answer questions:
RACE OF RESPONDENT
 
-What is the probability of selecting a respondent who is white?

Accepted Answer

A)   .13
B)   .14
C)   .27
D)   .73

Question 9

Determining the probability in question 4 utilizes which of the following?

Accepted Answer

A)   z-scores
B)   addition rule of probability
C)   independent events
D)   multiplication rule of probability

Question 10

Suppose a hat contains slips of paper numbered 1-10. After selecting and setting aside numbers "4" and "7," what is the probability of pulling a "5" on your next attempt?

Accepted Answer

A)   0
B)   .08
C)   .13
D)   1

Question 11

Use the following table to answer questions:
RACE OF RESPONDENT
 
-What is the probability of selecting a respondent identifying as either white or other?

Accepted Answer

A)   .14
B)   .27
C)   .73
D)   .86

Question 12

If a hat contains slips of paper numbered 1-10, what is the probability of pulling a "5" on your first attempt?

Accepted Answer

A)   0
B)   .1
C)   .5
D)   1

Question 13

When flipping a coin twice the second flip is not influenced by the first. What is this an example of?

Accepted Answer

A)   disjoint events
B)   addition rule of probability
C)   independent events
D)   multiplication rule of probability

Question 14

To determine the probability of pulling one of ten names out of a hat, we must divide the number of attempts by 	-----------.

Accepted Answer

A)   1
B)   2
C)   5
D)   10

Question 15

A z-score of -1.5 is associated with a higher probability of an event occurring than a z-score of 1.2.

Accepted Answer

A) True 
 B)False

Question 16

Suppose a statistics class has a distribution of grades with a mean of 70 and standard deviation of 15. Use this information to answer the following questions. a. What score is at the 75^th percentile? b. What is the z-score associated with a raw score of 60? c.What is the z-score associated with a raw score of 70? d.What is the probability of scoring a 90 or higher in this class? e.What is the probability of achieving agrade between 60 and 80 in this class? f.What is the probability of scoring a 50 or higher? g.What score is at the 40^th percentile?

Accepted Answer

The answer of Suppose a statistics class has a distribution...

Question 17

Suppose we have data on employees who earn an average wage of $22.00 per hour. If the standard deviation of wages is $4.00 per hour, what percentage of workers earn between $19.00 and $25.00?

Accepted Answer

A)   27
B)   54.6
C)   89.4
D)   90

Question 18

On a standard, six-sided die, what is the probability of rolling a "2" or "5" on the first roll and a "6" on the second?

Accepted Answer

A)   0
B)   .06
C)   .17
D)   .33

Question 19

If a statistics class has a distribution of grades with a mean of 70 and standard deviation of 15, what is the probability of a student scoring between a 70 and 90?

Accepted Answer

A)   .20
B)   .41
C)   .50
D)   .61

Question 20

On a standard, six-sided die, what is the probability of rolling a "2," "5," or "6"?

Accepted Answer

A)   0
B)   .33
C)   .5
D)   .67

Exam 5: Probability and the Normal Curve

What do z-scores represent?

Relative frequency refers to the proportion of times that we observe an event occurring.

When calculating the probability of pulling one of ten names out of a hat, the denominator is the -------------.

Drawing a card from a deck, returning it, and then determining the probability of drawing the same card is an example of probability without replacement.

Use the following table to answer questions: RACE OF RESPONDENT -What is the probability of consecutively selecting two white respondents?

Use the following table to answer questions: RACE OF RESPONDENT -What is the probability of selecting a respondent who is black?

Use the following table to answer questions: RACE OF RESPONDENT -What is the probability of selecting a respondent who is white?