Analyzing Scatterplots

What does a correlation coefficient measure?

• The number of points in a scatterplot

• The total range of x-values

• The strength and direction of a relationship

• The number of outliers.

If the correlation coefficient is -0.9, what does this indicate?

• A weak positive relationship

• A strong negative relationship

• No relationship

• A moderate positive relationship

What is the key difference between correlation and causation?

• Correlation proves one variable causes another

• Causation shows two variables move together

• Causation means the variables are unrelated

• Correlation shows patterns, but causation shows direct influence

Which scatterplot shows no correlation?

• A downward trend

• An upward trend

• A random cluster of points

• A straight line

Which statement about the line of best fit is true?

• It shows the general trend of the data

• It passes through every data point

• It is always a perfect predictor

• It only applies to non-linear data

Scatterplot shows a weak positive trend. What is a likely correlation coefficient?

• -0.8

• 0.9

• 0.3

• 1.0

A study finds that students who do more homework score higher on tests. Which conclusion is valid?

• More homework is correlated with higher scores

• Homework causes lower test scores

• Test scores improve homework quality

• There is no relationship

Which model best fits a scatterplot with points forming a U-shaped pattern?

• Linear

• Quadratic

• Exponential

• Logarithmic

A scientist finds r = 0.95 for hours of sunlight and plant growth. What does this mean?

• Sunlight discourages growth

• There's a strong positive correlation between sunlight and growth

• Plants do not need sunlight

• The data is corrupted by inaccuracies.

Which situation most likely shows a causal relationship?

• Ice cream sales and drowning rates

• Shoe size and reading ability

• Studying and higher grades

• Number of TVs and life expectancy