Year 9 Science · Unit 4 · Lesson 13
Apply Worksheet
Learning Goals
True or False? Fix the false ones
Circle T or F for each statement. If the statement is false, rewrite it correctly on the line below.
Univariate analysis looks at one variable, while bivariate analysis compares two variables.
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A dot plot is the best display for showing a relationship between two numerical variables.
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If points on a scatter plot fall from upper left to lower right, the trend is negative.
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A clear trend on a scatter plot proves that one variable causes the other.
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Scenario
A Year 9 student, Marcus, surveys his class. For each student he records two things: the number of hours they studied for the last test, and the mark they scored out of 20. He wants to know whether students who studied more tended to score higher.
(a) Is Marcus's question univariate or bivariate? Justify your answer by counting the variables.
(b) Which display should Marcus use, and what should each point on it represent? Explain.
(c) The points on Marcus's scatter plot rise from lower left to upper right. Describe the trend, and state what it suggests about study time and marks.
1. The scatter plot below shows the height (cm) and arm span (cm) of eight students. Describe the direction of the trend, comment on whether it looks strong or weak, and say what kind of analysis this is.
2. A class measures the resting heart rate of every student to find the typical value. Explain why this is univariate analysis, and name a display they could use.
Wrap Up
In one sentence, what was the main idea of this lesson?