Chapter 2 Review: Standard Deviation, Z-Scores, The Empirical Rule, and the Standard Normal Distribution

Multiple Choice

What is another name for the Empirical Rule?

• The 68-99-99.7 Rule

• The 68-98-99.7 Rule

• The 68-95-99.7 Rule

• The 65-98-99.6 Rule

Multiple Choice

Standard deviation can be a negative number.

• True

• False

Multiple Choice

Which histogram represents data with the larger standard deviation?

• Histogram A

• Histogram B

Multiple Choice

Which histogram represents data with the larger standard deviation?

• Histogram A

• Histogram B

Multiple Choice

Z-scores can be negative numbers.

• True

• False

Multiple Choice

Calculate the z-score:

Mean = 22, SD = 3.1, x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Multiple Choice

Calculate the mean:

z-score = -0.4, SD = 7, x = 20

• 22.8

• 17.2

• 22.04

• 32.5

Multiple Choice

Calculate x:

z-score = -2.2, mean = 25, SD = 7

• 9.6

• -36

• 5.2

• 23.46

Multiple Choice

Which symbol is commonly used to represent the center of normally distributed dataset?

• μ
• δ
• Σ
• Ζ

Multiple Choice

What is the total area under the normal curve?

• 1
• .9998
• .997
• -3 < z < 3

Multiple Choice

According to the empirical rule, how much of the data falls within 3 standard deviations?

• 25%
• 68%
• 95%
• 99.7%

Multiple Choice

What percentage of the data is between 0 and -1 standard deviations

• 34%

• 50%

• 2.35%

• 13.5%

Multiple Choice

Which of the following is a disadvantage of the Empirical Rule?

• There is no result for 3 standard deviations.

• It is very conservative.

• There is no result for 1 standard deviation.

• The data has to be approximately normal.

Multiple Choice

What percent of scores are below a z-score of $$z=2.34$$ ?  (Use Table A)

• 99.04%

• 0.96%

• 98.93%

• 97.68%

Multiple Choice

The standard normal table displays the percentage/percentile of data to the LEFT of the specified z-score.

• True

• False

Multiple Choice

Taylor's score on a test gives them a Z-score is -1.50. What does this mean?

• Joanne didn't take the test yet.

• Joanne's test score is 1.50 standard deviations below the average test score.

• Joanne did better than 1.50 times her peers.

• Joanne's test score, on average, was 1.5 points lower than the other test scores.

Multiple Choice

If I tell you that you scored at the 55th percentile on your final exam, you would know:

• 55% of the class scored the same or worse than you did

• You earned a 55% on the exam

• You failed the exam

• 45% of the class scored worse than you did

Multiple Choice

Luis scored 2.1 standard deviations above the mean on his recent test. What percentile does that place Luis in?

• The 98th percentile

• The first percentile

• Percentile .98214

• Percentile .01786