Statistics Final Exam Review

In a factory, the weight of the concrete poured into a mold by a machine follows a normal distribution with a mean of 1150 pounds and a standard deviation of 22 pounds. According to the Empirical Rule, approximately 95% of molds filled by this machine will hold weights in what interval?

• 1084 to 1216 pounds 

• 1106 to 1150 pounds 

• 1106 to 1194 pounds 

• 1128 to 1172 pounds

The data set below has an outlier of 42.
2, 5, 12, 15, 19, 4, 6, 11, 16, 18, 12, 12, 42
What effect does removing the outlier have on the distribution of the data?

• The mean will decrease

• The median will decrease

• The mean will increase

• The median will increase

How do you test for an outlier?

• 1.5xRange, add to Q3 and subtract from Q1

• 1.5x IQR, add to Q3 and subtract from Q1

• IQR, add to Q3 and subtract from Q1

• If the number seems really large or really small, it's probably an outlier

If heights of 3rd graders follow a normal distribution with a mean of 52 inches and a standard deviation of 2.5 inches, what is the z score of a 3rd grader who is 47 inches tall? 

• -5

• -2

• 2

• 5

Describe the shape of the data.

• Symmetrical

• Skewed Left

• Skewed Right

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. Using your standard normal table, what percentage of students at the high school have a GPA between 2.3 and 3.5?

• 68%

• 99.7%

• 95%

• 84%

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E

• A

• B

• C

• D

• E