Scatter Plot Problems

The equation of the line of best fit of a scatter plot is
y = –7x – 2. What is the the y-intercept?

• -9

• -2

• 2

• -7x

The equation of the line of best fit of a scatter plot is
 y = –8x + 3. What is the the y-intercept?

• 11

• -5x

• 3

• y= mx + b

The following scatterplot was based on data of size in square feet (x) of several houses and price in dollars (y).

Is there a relationship between the two variables?

• There appears to be a negative linear relationship.

• There appears to be a positive linear relationship.

• There does not appear to be any linear relationship.

• There appears to be a non-linear relationship.

Does there appear to be an outlier in the data?

• Yes, the top, right data point could be considered an outlier.

• No, there is no outlier in the data.

• Yes, the bottom left data point appears to be an outlier.

• There appears to be a non-linear relationship.

The scatter plot representing the percent correct of stuents taking the NAEP is shown. Select each true statment in regards to to the scatter plot.

• The states represented by the points in the lower left corner of the scatter plot did not to as well on Questions 7 and 15 as the other states.

• There is one state that did better than all of the other states on both questions.

• There is no correlation for the scores on questions 7 and 15.

• There appears to be a positive correlation, since students who did poorly on one question, typically did poorly on the other.

The scatter plot was constructed using data on length in inches (𝒙) of several alligators and weight in pounds (𝒚). Check each selection that represents the relationship between weight and length for these alligators.

• There appears to be a positive relationship between length and weight, but the relationship is not linear.

• There are three observations that stand out as outliers.

• There are three observations that stand out as outliers.

• Without the outliers, the relationship between lenth and weight appears to be linear.

This scatter plot was constructed using data on age in years (𝒙) of several Honda Civics and price in dollars (𝒚). Is there a relationship between age in years and price in dollars?

• Yes, there is a relationship.

• No, there is not a relationship.

This scatter plot was constructed using data on age in years (𝒙) of several Honda Civics and price in dollars (𝒚). Describe the relationship between age in years and price in dollars.

• There is not a relationship.

• There is a positive, linear relationship.

• There is a negative, linear relationship.

• The relationship in neither positive nor negative.

This scatter plot was constructed using data on age in years (𝒙) of several Honda Civics and price in dollars (𝒚). Is there an outlier in the data, if so, which point is it?

• There is no outliers in the data.

• There are two outliers, at 17 and 18 years in age.

• There is one outlier, at 10 years of age.

• Outlier? What's an outlier?

Samples of students in each of the U.S. states periodically take part in a large-scale assessment called the National Assessment of Educational Progress (NAEP). The table below shows the percent of students in the northeastern states (as defined by the U.S. Census Bureau) who answered Problems 7 and 15 correctly on the 2011 eighth-grade test. How many different points will be located on a scatter plot of this data?

• 8

• 9

• 27

• 58

Answer explanation

Although there are nine states in our table, two of the states (New Hampshire and Rhode Island) share the same data point (29, 52), so there will only be 8 data points on a scatter plot.