Calculating Pearson’s Correlation (VCE)

Calculate and interpret the mean and standard deviation of data and use these to compare data sets. Investigate the effect of individual data values including outliers, on the standard deviation(VCMSP372)

LO: To calculate Pearson’s Correlation (R) of a bivariate data set.
Know:

  • How to calculate the mean of a set of data
  • The definition of an outlier
  • How to square a number
  • How to find the square root of a number

Understand:
That calculating the standard deviation shows us how much the data differs from the average value of a set of data

Do:

  • I can calculate the standard deviation from a set of data
  • I can use the standard deviation to compare different sets of data
  • I can identify outliers and eliminate them to calculate the standard deviation of a set of data.

Visual Representations

Notes

Pearson’s correlation coefficient is a measure of the strength of the linear relationship between two variables. Basically it tells me how strongly one variable is related to another variable.

Pearson’s correlation (r) ranges from -1 to 1. -1 indicates a perfect negative linear relationship, while +1 indicates a perfect positive linear relationship.

Why do we use it?

  • Tells us how strongly things are related to each other.

Formula for Calculating Pearson’s r

Quick Steps:

  1. Mulitply both x and y values for each data pairing

  2. Find x squared of each data pairing

  3. Find y squared of each data pairing

  4. Find the summation of all x values, y values, xy values, x squared values and y squared values.

  5. Plug each of the values into the Pearson’s r formula above.

Pearson’s Correlation Videos

Practise Questions

My Maths 10/10A

Exercise 10C pg. 495 Q. 1-13