AP Statistics Review

How do I find the Interquartile Range (IQR) on a box plot?

• Add the min. and max.

• Add Q1 and Q3

• Subtract Q1 from Q3

• Subtract the min. from the max.

Students recorded the amount of minutes they spend watching TV. Using the box plot shown above, what is the median?

• 72

• 120

• 60

• 78

Which is TRUE?
I.  Random scatter in the residual plot indicates a linear model.
II.  If two variables are very strongly associated, then the correlation between them will be near 1 or -1.
III.  Changing the units of measurement for x or y changes the correlation coefficient.

• I only

• II only

• I and II only

• I, II and III

Which is the best CONTEXTUAL description of the y - intercept for the linear regression equation of the rats: Weight = 100 + 40(Time)?

• The y-intercept is 100, which means the rat is predicted to weigh 100 grams at birth. 

• The y-intercept is 100, which is where the graph crosses the y-axis. 

• 100 is where the data starts on the y-axis. 

• The y-intercept is 100, which means at a weight of 0, the rat will take 100 seconds.

“Least-squares” in the term “least-squares regression line” refers to...

• Minimizing the sum of the squares of all values of the explanatory variable.

• Minimizing the sum of the squares of all values of the response variable.

• Minimizing the products of each value of the response variable and the predicted value based on the regression equation.

• Minimizing the sum of the squares of the residuals.

Suppose a straight line is fit to data having response variable y and explanatory variable x.  Predicting values of y for values of x outside the range of the observed data is called...

• extrapolation

• causation

• correlation

• interpolation

Compute the probability of selecting either an Ace or a heart in a deck of 52 cards.

• 30.77%

• 32.69%

• 7.69%

• 25%

Suppose we toss a penny and a nickel. Let A be the event that the penny is a head and B be the event that the nickel is a tail. 
The events A and B are

• Disjoint

• complements

• independent

• dependent

There are 10 red marbles and 8 green marbles in a jar. If you take three marbles from the jar (without replacement), the probability that they are all red is: 

• 0.069

• 0.088

• 0.147

• 0.171

A recent study of 200 nurses found that of 125 female nurses, 56 had bachelor's degrees:  and of 75 male nurses, 34 had bachelor's degrees.  If a nurse is selected at random, find the probability that the nurse is a female or has a bachelor degree.

• 159/200

• 125/200

• 215/200

• 90/200