Deck 5: Probability and the Normal Curve

Question 1

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

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

Answer 1

10

Question 2

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

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

Answer 2

number of names

Question 3

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

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

Answer 3

.1

Question 4

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

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

Question 5

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

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

Question 6

Rolling a "1" on a standard die means that another number did not/cannot come up. What is this an example of?

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

Question 7

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?

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

Question 8

Determining the probability in question 7 utilizes which of the following?

A) z-scores
B) addition rule of probability
C) multiplication rule of probability
D) both b and c

Question 9

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

A) disjoint events
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?

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

Question 11

Determining the probability in question 10 utilizes which of the following?

A) probability without replacement
B) addition rule of probability
C) probability with replacement
D) multiplication rule of probability

Question 12

Use the following table to answer questions:
RACE OF RESPONDENT


-What is the probability of selecting a respondent who is white?

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

Question 13

Use the following table to answer questions:
RACE OF RESPONDENT


-What is the probability of selecting a respondent who is black?

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

Question 14

Use the following table to answer questions:
RACE OF RESPONDENT


-What is the probability of consecutively selecting a respondent who is white followed by a respondent who is black?

A) .10
B) .14
C) .27
D) .87

Question 15

Use the following table to answer questions:
RACE OF RESPONDENT


-What is the probability of consecutively selecting two white respondents?

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

Question 16

Use the following table to answer questions:
RACE OF RESPONDENT


-What is the probability of selecting a respondent identifying as either white or other?

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

Question 17

Which of the following z-scores encompasses the greatest area under the normal curve?

A) -2.2
B) -1.2
C) 0
D) 1.5

Question 18

If a statistics class has a distribution of grades with a mean of 70 and standard deviation of 15, what score is at the 90^th percentile?

A) 70
B) 85
C) 89
D) 92

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?

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

Question 20

If a statistics class has a distribution of grades with a mean of 70 and standard deviation of 15, what is the z-score associated with a raw score of 85?

A) -1
B) 0
C) 1
D) 1.5

Question 21

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?

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

Question 22

Probabilities are determined by dividing the number of outcomes in an event by the number of all possible outcomes that can occur.

Question 23

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

Question 24

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.

Question 25

As we move from .1 standard deviations up to 4 standard deviations we are steadily decreasing the percentage of cases that fall between the mean and the number of standard deviations from the mean.

Question 26

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

Question 27

What do z-scores represent?

Question 28

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?

Question 29

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?