Scatterplot Regression Review

A person travels by car.  They record their miles driven in a data table.  Calculate the linear regression equation of this data.

• y = 61.93x - 1.79

• y = -1.79x + 61.93

• y = 0.016x + 0.03

• y = 0.03x + 0.016

Which of the following statements is not true of the correlation r between the lengths in inches and weights in pounds of a sample of brook trout?

• r must take a value between -1 and 1.

• r is measured in inches.

• If longer trout tend to also be heavier, then r>0.

• r would not change if we measured the lengths of the trout in centimeters instead of inches.

Shown is a residual plot. Would a linear regression model of the data be most appropriate?

• YES

• NO

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

Mathematical Equivalence

ON

Roller coasters with larger heights usually go faster than shorter ones. Here is a scatterplot of x = height (in feet) versus y = maximum speed (in miles per hour) for a sample of 9 roller coasters. The equation of the regression line for this relationship is below. katex latex="y^{\wedge}=28.17+0.2143x" Use the regression line equation to predict the maximum speed for a roller coaster that is 175 feet tall. Round your answer to nearest whole number.

Mathematical Equivalence

ON

Does adding sugar to the water in a vase help flowers stay fresh? To find out, two statistics students went to a flower shop and randomly selected 12 carnations. When they got home, they students prepared 12 identical vases with exactly the same amount of water in each vase. They put 1 tablespoon of sugar in 3 vases, 2 tablespoons of sugar in 3 vases, and 3 tablespoons of sugar in 3 vases. In the remaining 3 vases, they added no sugar. After the vases were prepareed, the students randomly assigned 1 carnation to each vase and observed how many hours each flower continued to look fresh. Here is a scatterplot along with the regression line where x = amount of sugar (in tablespoons) and y = hours of freshness. Calculate the residual for the flower that had 2 tablespoons of sugar and looked fresh for 204 hours. Round your answer to the nearest tenth.

Mathematical Equivalence

ON

In the regression line to the left, what does "y-hat" represent?

• The slope

• The y-intercept

• The predicted value

• The residual

Mathematical Equivalence

ON

Mathematical Equivalence

ON