AP Stats Chapters 3-4 Review

The height (in feet) and volume (in cubic feet) of usable lumber of 32 cherry trees are measured by a researcher.

In this study, the response variable is...

• height of researcher.

• volume of lumber.

• height of tree.

• impossible to determine.

Which of the following statements are supported by the scatterplot?

I. There is a positive association between height and volume.

II. There is an outlier in the plot.

III. As the height of a cherry tree increases, the volume of useable lumber it yields increases.

• I, II, and III

• I only

• II only

• I and II only

If the data point (65,70) were removed from this study, how would the value of the correlation r change?

• r would not change, since it’s value does not depend which variable is used for x and which is used for y.

• r would be smaller, because this point falls in the pattern of the rest of the data.

• r would be larger, since this point does not fall in the pattern of the rest of the data.

• r would be smaller, since there are fewer data points.

You would draw a scatterplot to...

• show the distribution of heights of students in this course.
• show the relationship between gender and having a driver’s license.
• compare the distributions of heights for male and female students in this course.
• show the relationship between the height of female students and the heights of their mothers.

The correlation coefficient measures...

• whether there is a relationship between two variables.
  
• the strength of the relationship between two quantitative variables.
  
• whether a cause and effect relation exists between two variables.
  
• the strength of the linear relationship between two quantitative variables.
  

In the scatterplot, the point indicated by the open circle...

• has a negative value for the residual.
  
• has a positive value for the residual.
  
• has a zero value for the residual.
  
• is an outlier.

A study of the effects of television on child development measured how many hours of television each of 125 grade school children watched per week during a school year and each child’s reading score. Which variable would you put on the horizontal axis of a scatterplot of the data?

• Reading score, because it is the response variable.
  
• Reading score, because it is the explanatory variable.
  
• Hours of television, because it is the response variable.
  
• Hours of television, because it is the explanatory variable.
  

If removing an observation from a data set would have a marked change on the equation of the least-squares regression line, the point is called...

• resistant

• a residual

• influential

• a response

• an outlier

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...

• contingency

• extrapolation

• causation

• correlation

• interpolation

Above is the computer output for the regression of calories (x) and protein (y) in one cup of 11 varieties of dried beans. Which of the following statements is a correct interpretation of the slope of the regression line?

• For each 1 unit increase in calorie content, the predicted protein content increased by 2.08 grams.

• For each 1 unit increase in calorie content, the predicted protein content increased by 0.063 grams.

• For each 1 unit increase in protein content, the predicted calorie content increased by 2.08 grams.

• For each 1 unit increase in protein content, the predicted calorie content increased by 0.063 grams.

• For each 1 unit increase in protein content, the predicted calorie content increased by 0.024 grams.