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Scatterplot:
Response Variable:Outcome or Result
Explanatory VariableWhat you thinkis explaining or causing the response.
Shows the relationshipbetween two Quantitative variables from the same individual.
Unit 4: Describing Relationships
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2Example (Constructing a scatterplot) The professor swimsProfessor Moore swims 2000 yards regularly in a vain attempt to undo middle age. Here are his times (in minutes) and his pulse rate after swimming (in beats per minute) for 23 sessions in the pool:
Time 34.12 35.72 34.72 34.05 34.13 35.72 36.17 35.57 35.37 35.57 35.43 36.05Pulse 152 124 140 152 146 128 136 144 148 144 136 124
Time 34.85 34.70 34.75 33.93 34.60 34.00 34.35 35.62 35.68 35.28 35.97Pulse 148 144 140 156 136 148 148 132 124 132 139
(a) Identify the explanatory variable and the response variable.
(b) Make a scatterplot. Be sure to label and scale your axes.
(c) Describe what you see.
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Describing the relationship
Form
Direction
Strength
Interpreting Scatterplots
Positive association OR Negative association