Correlation

How to calculate arithmetic mean

1. Sum all individual elemets of the variable

2. Divide by the number of elements

How to calculate variance

1. Subtract each observation of each participant from the sample mean

2. Square that and add up all the values

3. Divide by n-1 where n = the number of observations

How to calculate standard deviation

Square root of variance

How to calculate covariance

1. Subtract the mean x from each x-value (xᵢ − x̄).

2. Subtract the mean y from each y-value (yᵢ − ȳ).

3. Multiply these two results for each pair.

4. Add up all those products.

5. Divide the total by (n − 1).

How to calculate correlation

1. Subtract the mean x from each x-value (xᵢ − x̄).

2. Subtract the mean y from each y-value (yᵢ − ȳ).

3. Multiply these two results for each pair.

4. Add up all those products.

5. Multiply SD of x by SD of y

6. Divide the first part by the second