Question 1

A score that is 2.5 standard deviations below the mean would have a z score of _______.

Accepted Answer

A) 2.5 
B) −2.5 
C) 0 
D) 25 
A) 2.5 
B) −2.5 
C) 0 
D) 25 B

Question 2

Under the normal curve, approximately what percentage of scores falls between −1 and +1 standard deviations around the mean?

Accepted Answer

A) 14% 
B) 34% 
C) 68% 
D) 95% 
A) 14% 
B) 34% 
C) 68% 
D) 95% C

Question 3

Which of the following is true of z scores that fall above the mean?

Accepted Answer

A) They are negative. 
B) They are positive. 
C) They are equal to zero. 
D) They are equal to one. 
A) They are negative. 
B) They are positive. 
C) They are equal to zero. 
D) They are equal to one. B

Question 4

Which of the following characteristics is associated with the "tails" of the normal curve?

Accepted Answer

A) asymptotic 
B) symmetry 
C) probability 
D) bell-shape 
A) asymptotic 
B) symmetry 
C) probability 
D) bell-shape

Question 5

The _______ is the most commonly used standard score.

Accepted Answer

A) z score 
B) t score 
C) f score 
D) p score 
A) z score 
B) t score 
C) f score 
D) p score

Question 6

What is the z score for a raw score of 85 where the group mean is 75, and the standard deviation is 5?

Accepted Answer

A) −2.0 
B) 2.5 
C) 2.0 
D) −2.5 
A) −2.0 
B) 2.5 
C) 2.0 
D) −2.5

Question 7

What is the standard used by statisticians to determine the probability of an event occurring outside of chance alone?

Accepted Answer

A) 0.05% 
B) 5% 
C) 95% 
D) 99% 
A) 0.05% 
B) 5% 
C) 95% 
D) 99%

Question 8

What is the foundation of inferential statistics?

Accepted Answer

A) probability 
B) linear algebra 
C) mathematical proofs 
D) Algebra 
A) probability 
B) linear algebra 
C) mathematical proofs 
D) Algebra

Question 9

What is the term associated with how flat or peaked a distribution appears?

Accepted Answer

A) ogive 
B) skewness 
C) kurtosis 
D) variability 
A) ogive 
B) skewness 
C) kurtosis 
D) variability

Question 10

What percentage of all scores fall above a z score of +1?

Accepted Answer

A) 16% 
B) 34% 
C) 50% 
D) 84% 
A) 16% 
B) 34% 
C) 50% 
D) 84%

Question 11

When we want to infer from a sample to the population, what assumption must be met?

Accepted Answer

A) The sample is normally distributed. 
B) The sample is large. 
C) The population is normally distributed. 
D) The population is large. 
A) The sample is normally distributed. 
B) The sample is large. 
C) The population is normally distributed. 
D) The population is large.

Question 12

If a distribution has a mean of 1,000 and a standard deviation of 100, how many standard deviations is 600 from the mean?

Accepted Answer

A) −2 
B) −4 
C) 4 
D) 2 
A) −2 
B) −4 
C) 4 
D) 2

Question 13

The entire normal curve contains _______ of scores.

Accepted Answer

A) 25% 
B) 50% 
C) 99.9% 
D) 100% 
A) 25% 
B) 50% 
C) 99.9% 
D) 100%

Question 14

Are distributions always normal?

Accepted Answer

No, some distributions are not

Question 15

Why is it important that the tails of a normal curve never touch the x-axis?

Accepted Answer

The fact that they do not touch means th

Question 16

What percentage of all scores fall below a z score of +1?

Accepted Answer

A) 16% 
B) 34% 
C) 50% 
D) 84% 
A) 16% 
B) 34% 
C) 50% 
D) 84%

Question 17

When most people scored high on a test of knitting knowledge, and very few people scored low, what is the distribution called?

Accepted Answer

A) platykurtic 
B) leptokurtic 
C) positively skewed 
D) negatively skewed 
A) platykurtic 
B) leptokurtic 
C) positively skewed 
D) negatively skewed

Question 18

The study of probability is the basis for determining the degree of confidence we have in stating that a particular finding or outcome is true.

Accepted Answer

A) True 
 B)False

Question 19

A distribution of scores in which almost the entire class scored very low, but a few students scored fairly high would be ______.

Accepted Answer

A) positively skewed 
B) negatively skewed 
C) unskewed 
D) normally distributed 
A) positively skewed 
B) negatively skewed 
C) unskewed 
D) normally distributed

Question 20

What percentage of scores fall between the following z scores: −1 to +1; −1 to +2; and −1 to +3?

Accepted Answer

Range of z scores Pe

Exam 8: Are Your Curves Normal Probability and Why It Counts

A score that is 2.5 standard deviations below the mean would have a z score of _______.

Under the normal curve, approximately what percentage of scores falls between −1 and +1 standard deviations around the mean?

Which of the following is true of z scores that fall above the mean?

Which of the following characteristics is associated with the "tails" of the normal curve?

The _______ is the most commonly used standard score.

What is the z score for a raw score of 85 where the group mean is 75, and the standard deviation is 5?

What is the standard used by statisticians to determine the probability of an event occurring outside of chance alone?

What is the foundation of inferential statistics?

What is the term associated with how flat or peaked a distribution appears?

What percentage of all scores fall above a z score of +1?

When we want to infer from a sample to the population, what assumption must be met?

If a distribution has a mean of 1,000 and a standard deviation of 100, how many standard deviations is 600 from the mean?

The entire normal curve contains _______ of scores.

Are distributions always normal?

Why is it important that the tails of a normal curve never touch the x-axis?

What percentage of all scores fall below a z score of +1?

When most people scored high on a test of knitting knowledge, and very few people scored low, what is the distribution called?

The study of probability is the basis for determining the degree of confidence we have in stating that a particular finding or outcome is true.

A distribution of scores in which almost the entire class scored very low, but a few students scored fairly high would be ______.

What percentage of scores fall between the following z scores: −1 to +1; −1 to +2; and −1 to +3?

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