Gr12 Mathematics: Ch 8.2 Correlation

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What does a correlation coefficient of -0.8 indicate?

No correlation
A moderate positive correlation
A strong negative correlation (correct)
A very weak negative correlation

What is the formula to calculate the linear correlation coefficient, r?

r = σx / σy
r = b × σx × σy
r = σx - σy
r = b(σx / σy) (correct)

What does a correlation coefficient of 0.4 indicate?

A strong negative correlation
No correlation
A moderate positive correlation (correct)
A very weak positive correlation

What is the range of values for the correlation coefficient, r?

[-1, 1] (B) Signup and view all the answers

What does a correlation coefficient of 1 indicate?

A perfect positive correlation (A) Signup and view all the answers

What is the name of the formula used to calculate the linear correlation coefficient?

Pearson's product moment correlation coefficient (A) Signup and view all the answers

What does a correlation coefficient of -1 indicate?

A perfect negative correlation (D) Signup and view all the answers

What is the interpretation of a correlation coefficient, r, that is close to 0?

No correlation (C) Signup and view all the answers

What is the direction of the correlation when the linear correlation coefficient is positive?

As x increases, y increases. (A) Signup and view all the answers

What is the strength of the correlation when the linear correlation coefficient is 0.6?

Moderate correlation (B) Signup and view all the answers

What is the name of the correlation coefficient when it is equal to -1?

Perfect negative correlation (A) Signup and view all the answers

What is the unit of measurement for the standard deviation of x-values and y-values?

Units of x and y (D) Signup and view all the answers

What is the term for the gradient of the least squares regression line?

b (B) Signup and view all the answers

What is the correlation coefficient when there is no relationship between the two variables?

r = 0 (B) Signup and view all the answers

What is the correlation coefficient when the increase in one variable leads to a decrease in the other variable?

r < 0 (C) Signup and view all the answers

What is the term for the correlation coefficient that is calculated using the formula r = b(sigma_x/sigma_y)?

Pearson’s product moment correlation coefficient (B) Signup and view all the answers

What is the term used to describe the strength and direction of a relationship between two variables?

Correlation coefficient (C) Signup and view all the answers

A correlation coefficient, r, of 0.32 indicates a _______ correlation.

Weak (A) Signup and view all the answers

Which of the following is NOT a characteristic of a perfect negative correlation?

r = 0 (B) Signup and view all the answers

What happens to the value of y when the value of x increases in a correlation with a coefficient, r, of -0.6?

y decreases (B) Signup and view all the answers

What is the name of the correlation coefficient that is calculated using the formula r = b(sigma_x/sigma_y)?

Pearson's product moment correlation coefficient (A) Signup and view all the answers

A correlation coefficient, r, of 0.85 indicates a _______ correlation.

Strong (D) Signup and view all the answers

Which of the following is a characteristic of a correlation with a coefficient, r, of 0?

There is no correlation between the variables (D) Signup and view all the answers

What is the interpretation of a correlation coefficient, r, that is close to 1?

Perfect positive correlation (C) Signup and view all the answers