AP Statistics Review

The "Emperical Rule" states that the normal distribution contains 99.7% of the data between how many standard deviations?

• 3

• 1

• 2

• 10

How do we determine an upper end outlier of a distribution?

• Mean + 3(IQR)

• Median +3(IQR)

• Q3 +1.5(IQR)

• Maximum - .5(IQR)

The five number summary for a one-variable dataset is {5, 28, 29, 42, 75}. If you wanted to construct a modified boxplot for the dataset (that is, one that would show outliers if there are any), what would be the maximum possible length of the right side “whisker”?

• 21

• 42

• 33

• 14

A study was done on the relationship between high school grade point average (GPA) and scores on the SAT. The following 8 scores were from a random sample of students taking the exam:  
x(GPA)  3.2  3.7  3.9  3.1  3.6  2.5  2.9  3.5  
y(SAT)  725  743  745  665  700  562  590  740
What is the percent of variation in SAT scores is accounted for by the LSRL? 

• 0.98

• 0.35

• -0.35

• 0.12

A least-squares regression line for predicting performance on a college entrance exam based on high school grade point average (GPA) is determined to be
predicted score = 273.5 + 91.2(GPA)
One student in the study had a high school GPA of 3.2 and an exam score of 550.  What is the residual for this student? 

• 15.34

• 40.23

• -40.23

• -15.34

The proportion of observations from a standard normal distribution that take values larger than 0.75 is about

• 0.2266

• 0.2500

• 0.7704

• 0.8023

The correlation coefficient is represented by what? 

• r

• r^2

• s

• c

The correlation coefficient measures

• whether there is a relationship between two variables

• the strength of the relationship between two quantitative variables

• whether or not a scatterplot shows an interesting pattern

• the strength of the linear relationship between two quantitative variables

Which of the following is true of the correlation r? 

• It is a resistant measure of association

• It's between -1 and 1 inclusively. 

• If r is the correlation between X and Y, then -r is the correlation between Y and X

• Whenever all the data lie on a perfectly straight-line, the correlation will always be equal to +1.0

A slice of pizza from a certain restaurant has an average area of 40 square inches with a standard deviation of 5 square inches. Assuming the distribution of areas is approximately normal, what proportion of slices will be between 35 and 50 square inches

• 68%

• 81.5%

• 34%

• 95%