Empirical

Multiple Choice

What shape is a normal distribution curve?

• Half curve
• Round curve
• Bell curve
• Square curve

Multiple Choice

The sign of the z-score indicates whether the location is above(positive) or below(negative) the mean.

• True

• False

Multiple Choice

Find the z-scores value corresponding if the location is above the mean by 1/2 standard deviations

• -0.50

• +1.00

• +0.50

• -1.00

Multiple Choice

Find the z-score value corresponding if the location is below the mean by 2 standard deviations

• +2.00

• -2.00

• +1.25

• -1.00

Multiple Choice

Find the Z-score.

Mean = 22

Standard Deviation: 3.1

x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Multiple Choice

Find the Z-score.

Mean = 21

Standard Deviation: 1.3

x = 22

• 0.77

• 5.33

• 1.07

• 1.26

Multiple Choice

Find the z-score.

Mean = 38

Standard Deviation: 1.2

x = 42

• 3.33

• -3

• 3.03

• -3.33

Multiple Choice

Find the z-score.

Mean = 40

Standard Deviation: 1.4

x = 42

• 1.43

• 1.28

• -1.4

• 1.24

Multiple Choice

Find the z-score.

Mean: 29.8

Standard Deviation: 7

x = 20

• -1.4

• 10.2

• -21

• 35

Multiple Choice

A data set has a mean of 300 and a standard deviation of 40. What value would have a z-score of $$z=-2$$  ?

• 298

• 296

• 220

• 380

Multiple Choice

According to the empirical rule, what percentage of data falls within 1 standard deviation? 

• 25%
• 68%
• 95%
• 99.7%

Multiple Choice

The center of the curve represents what value of a data set?

• μ
• δ
• Σ
• Ζ

Multiple Choice

What type of distribution is pictured?

• Right skewed

• Left skewed

• Random

• Normal

Multiple Choice

A grading scale is set up for 1000 students’ test scores. It is assumed that the scores are normally distributed with a mean score of 75 and a standard deviation of 15. Calculate the score that lies -2 standard deviation from the mean.

• 60

• 475

• 45

• 9500

Multiple Choice

In an Oreo factory, the mean mass of a cookie is given as 40 g. For quality control, the standard deviation is 2 g. If 10 000 cookies were produced, how many cookies are within 2 g of the mean?

• 6800

• 9500

• 3200

• 9750

Multiple Choice

Suppose the heights of adult men are normally distributed. The heights of a sample of 30 men are shown below in inches.

65, 83, 69, 67, 69, 67, 67, 72, 85, 68, 73, 65, 67, 65, 72, 71, 67, 73, 68, 72, 61, 75, 66, 78, 65, 71, 68, 76, 67, 68

Compute the standard deviation of the sample. (Use stdev)

• 5.31

• 70

• 5.23

• 68

Multiple Choice

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days. About what percent of the products last between 12 and 15 days?

• 68%

• 99.7%

• 95%

• 34%

Multiple Choice

The mean life of a tire is 30 000 km. The standard deviation is 2000 km. 68% of all tires will have a life between ______km and ______km.

• 26000 and 34000

• 28000 and 32000

• 24000 and 34000

• 22000 and 36000

Multiple Choice

Suppose the heights of adult men are normally distributed. The heights of a sample of 30 men are shown below in inches.

65, 83, 69, 67, 69, 67, 67, 72, 85, 68, 73, 65, 67, 65, 72, 71, 67, 73, 68, 72, 61, 75, 66, 78, 65, 71, 68, 76, 67, 68

Compute the mean of the sample.

• 71

• 70

• 69

• 68

Multiple Choice

The distribution above is normal. What percent lies below the curve?

• 68%

• 95%

• 99.7%

• 100%

Multiple Choice

What is the total area under the curve?

• 1
• .9998
• .997
• -3 < z < 3

Multiple Choice

The distribution above is normal. What percent lies between ±3 standard deviations?

• 68%

• 95%

• 99.7%

• .3%

Multiple Choice

According to the empirical rule, what percentage of data falls within 1 standard deviation? 

• 25%
• 68%
• 95%
• 99.7%

Multiple Choice

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

• 25%
• 68%
• 95%
• 99.7%

Multiple Choice

Use the following information and the Empirical Rule to estimate the answer.

The ages of golfers are normally distributed, with a mean of 38 and a standard deviation of 4.

Find the percentage of golfers that are between 30 and 46 years old.

• 68%

• 94%

• 95%

• 99.7%

Multiple Choice

What type of association does this graph have?

• positive
• negative
• none
• all of the above

Multiple Choice

What type of correlation does this scatter plot show?

• Positive correlation

• Negative correlation

• No correlation

• Constant correlation

Multiple Choice

Which graph depicts the strongest positive correlation?

Multiple Choice

• Positive, strong
• Positive, weak
• Negative, strong
• Negative weak

Multiple Choice

r=-0.89

• Strong positive 
• Weak positive 
• Strong negative 
• Weak negative 

Multiple Choice

What is the percentage of data that falls within one standard deviation of the mean?

• 67%

• 65%

• 72%

• 68%

Multiple Choice

What is the percentage of data that falls within two standard deviations of the mean?

• 68%

• 99.7%

• 95%

• 98%

Multiple Choice

What percent of people within 2 standard deviations of the mean?

• 99.7

• 34

• 68

• 95

Multiple Choice

What percent of people within 3 standard deviations of the mean?

• 99.7

• 34

• 68

• 95

Multiple Choice

The Empirical (68-95-99.7) Rule can be applied only if data is ....

• Normally Distributed

• Uniform

• Skewed

• Symmetric

Multiple Choice

The Empirical Rule's percents are:

• 68-95.7-99

• 68-95-99.7

• 68.7-95-99