Linear Correlation & Regression

Add up the values in the x-column (number of siblings)

Add up the y-values (overall mark)

Square each of the y-values first (overall mark) then add them up

Multiply x by y (siblings times mark) then add up the results

Square each of the x-values first (number of siblings) then add them up

The correlation coefficient measures the strength and direction of the linear relationship between two variables. In this case, the correlation coefficient is -0.95, which indicates a strong negative linear relationship between the variables. This means that as one variable increases, the other variable tends to decrease. The negative sign indicates the direction of the relationship, and the absolute value of 0.95 indicates the strength, with values closer to 1 indicating a stronger relationship.

Based on the information given, there is no direct correlation between a person's mark of 78 and the number of siblings they would have. The answer of 2 is likely a random guess or unrelated to the question. Without further context or information, it is not possible to determine the number of siblings a person would have based solely on their mark.

The slope of the line of best fit is equal to the given value of -8.13.

Interpolation is the process of estimating values within a set of known data points. In this case, determining the number of siblings for a person with a mark of 78 falls within the range of known data points, so it is considered interpolation. Extrapolation, on the other hand, involves estimating values outside the range of known data points, which is not applicable in this scenario. Therefore, the correct answer is interpolation.

What does the correlation coefficient tell you about the relationship?
Hint: You should have 4 terms in your classification!!

Remember y-bar is the mean of y, and x-bar is the mean of x.

Substitute into your equation for x=6.

Is 6 siblings between your min & max number of siblings given, or outside of this range?

y=ax+b