# Statistics E4 Scatter Plots.

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Statistics E4 Scatter Plots

E4 Scatter Plots Positive Correlation – _________ pattern upward
Negative Correlation – _________ pattern downward No Correlation – _____ pattern no

Example 1 negative positive none What kind of pattern is this?
upward, downwards, or no pattern no pattern upwards downwards

Line of Best Fit __________ line that is “closest” to a set of data points STRAIGHT You do NOT connect all the points! Just draw a STRAIGHT line through most of the points

Line of Best Fit About 650 million
Example 2: The scatter plot shows the number of CD’s (in millions) that were sold from 1999 to If the trend continues, about how many CD’s were sold in 2006? Draw a straight line that represents the pattern of the data About 650 million 2006

Line of Best Fit Example 3: The number of hours spent on math homework each week and the final exam grades for twelve students in Mr. Dylan’s algebra class are plotted on the graph A. What type of correlation is it? (1) positive negative (3) no correlation (4) cannot be determined Draw a straight line that represents the pattern of the data

Line of Best Fit B: Based on a line of best fit, which exam grade is the best prediction for a student who spends about 4 hours on math homework each week? (1) 62 72 (3) 82 (4) 92

In Closing Explain why a line of best fit does not connect the dots like a line graph

Practice Problems Now try the practice problems on your own