Topic 4 Lessons 1-4

What does Point A on the graph represent?

What is a scatter plot?

• A table of measurement data used to construct a graph

• A display of points that shows the relationship between two sets of data

• A graph that has several different lines scattered on a coordinate plane

• A graph that is nonlinear

What might the outlier represent?

Select all the true statements about the scatter plots in items 1 and 4.

• The art show attendance scatter plot shows a positive association.

• The shark size scatter plot shows a positive association.

• No association means that the y-values increase as the x-values increase.

• These scatter plots show the associations between two sets of paired data.

• A shark of length 90 cm weighed 300 kg.

Draw a trend line in the scatter plot. Then describe the relationship between the two sets of data.

Answer explanation

The trend line describes a weak negative association.

Using the scatter plot, select all the true statements.

• There is a strong positive linear association.

• There is a weak negative association.

• There are 3 gaps on the scatter plot.

• There is an outlier at (75, 7).

• The trend line is accurately placed.

Which statement is true about using scatter plots to make predictions?

• You cannot make predictions by visually using the trend line.

• Any two points can be used to draw a trend line.

• All you need is the slope of the trend line.

• You can use the equation of a trend line to find the y-value of a given x-value.

What are the slope and y-intercept of the line?

• The slope is approximately 3 and the y-intercept is 2.

• The slope is approximately 1.33 and the y-intercept is 2.

• The slope is approximately 2 and the y-intercept is 3.

• The slope is approximately 2 and the y-intercept is 1.33.

The scatter plot at the right shows the time spent studying compared to test scores for Mr. Stone’s eighth-grade class. Predict the score that a student would earn if she studied for 7 hours. Round your answer to the nearest whole number.

• 87

• 75

• 92

• 80

What does the number in the bottom right-hand corner of a two-way frequency table represent?