Gr12 Mathematics: Ch 8 Sum Statistics

Play an AI-generated podcast conversation about this lesson

What is the value of r if there is no correlation between x and y?

1
-1
0.5
0 (correct)

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

r = b * σx * σy
r = σx / σy
r = b(σx / σy) (correct)
r = σy / σx

What does a positive value of r indicate?

As x increases, y decreases.
As x increases, y increases. (correct)
The correlation is perfect.
There is no correlation between x and y.

What is the range of values for r that indicates a very weak correlation?

0 < r < 0.25 (A) Signup and view all the answers

What is the value of r if there is a perfect negative correlation between x and y?

-1 (B) Signup and view all the answers

What is the term used to describe the correlation coefficient r?

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

What is the equation of the linear regression line?

y = A + Bx (A) Signup and view all the answers

What does a correlation coefficient of -0.6 indicate?

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

What is the purpose of the regression coefficient?

To measure the strength of correlation between two sets of data (B) Signup and view all the answers

What is the range of values for the correlation coefficient?

-1 to 1 (B) Signup and view all the answers

What does a correlation coefficient of 0.2 indicate?

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

What is the first step in using a calculator for linear regression?

Switch to STAT mode (A) Signup and view all the answers

What does a correlation coefficient of -1 indicate?

A strong negative correlation (C) Signup and view all the answers

What is the interpretation of a negative correlation?

As x increases, y decreases (C) Signup and view all the answers

What does a correlation coefficient of 0.8 indicate?

A strong positive correlation (B) Signup and view all the answers

If the correlation coefficient r is -0.4, what can be said about the relationship between x and y?

As x increases, y decreases (C) Signup and view all the answers

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

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

If the correlation coefficient r is -0.95, what can be said about the relationship between x and y?

There is a very strong negative correlation (A) Signup and view all the answers

What is the reason why it is often easier to calculate the correlation coefficient r using a calculator?

Because the calculator can handle large datasets (D) Signup and view all the answers

If the correlation coefficient r is 0.1, what can be said about the relationship between x and y?

There is a very weak positive correlation (C) Signup and view all the answers

What does a correlation coefficient of 0.95 indicate?

A strong positive correlation between the variables. (D) Signup and view all the answers

Which of the following is true about the linear regression line?

It is the line of best fit for a set of bivariate numerical data. (B) Signup and view all the answers

What is the purpose of calculating the gradient (B) in linear regression?

To determine the slope of the regression line. (B) Signup and view all the answers

What does a correlation coefficient of -0.85 indicate?

A strong negative correlation between the variables. (B) Signup and view all the answers

What is the first step in using a calculator for linear regression analysis?

Switch to STAT mode. (C) Signup and view all the answers

What can be concluded about the relationship between x and y if the correlation coefficient (r) is -0.4?

There is a weak negative correlation between x and y. (A) Signup and view all the answers

What does the y-intercept (A) represent in the linear regression equation?

The point at which the regression line intersects the y-axis. (A) Signup and view all the answers

What is the interpretation of a correlation coefficient of 0.7?

A medium positive correlation between the variables. (C) Signup and view all the answers

What does a correlation coefficient of 0.6 indicate about the relationship between x and y?

A moderate correlation (A) Signup and view all the answers

What is the purpose of calculating the correlation coefficient r?

To determine the strength and direction of the correlation (A) Signup and view all the answers

What is the interpretation of a correlation coefficient of -0.8?

A strong negative correlation (C) Signup and view all the answers

What happens to y when x increases and the correlation coefficient r is 0.4?

y increases (B) Signup and view all the answers

What can be said about the relationship between x and y if the correlation coefficient r is 0.9?

There is a very strong positive correlation (D) Signup and view all the answers

What does a correlation coefficient of 0 indicate about the relationship between x and y?

No correlation (A) Signup and view all the answers

What is the primary purpose of the linear regression line?

To model the relationship between two variables (D) Signup and view all the answers

What does a correlation coefficient of -0.7 indicate?

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

What is the value of the correlation coefficient if there is a perfect positive correlation?

1 (D) Signup and view all the answers

What does the gradient (B) represent in the linear regression equation?

The slope of the line (D) Signup and view all the answers

What is the interpretation of a zero correlation coefficient?

No relationship between the variables (B) Signup and view all the answers