Problem 55225. Simpson's Paradox - Calculate correlation coefficients for groups of data

• Created by Matt Tearle
• Appears in MATLAB Fundamentals - Matrices and Arrays

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Simpson's Paradox is a statistical phenomenon where groups of data can have a characteristic while the whole data set together has the opposite characteristic. In the example below, both groups have a negative correlation between x and y, but collectively there is a positive correlation.

Write a function that takes three vectors as input: x, y, and g. The vector g will contain only the values 1 and 2. The function should return three outputs. These outputs are the Pearson correlation coefficients for three different groupings of the data, which are: (1) for all x and y, (2) x and y corresponding to elements where g has the value 1, (3) x and y for which g is 2.

[c,c1,c2] = groupcorr(x,y,g)

c =

0.8800

c1 =

-0.6800

c2 =

-0.4396

Solve

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39.62% Correct | 60.38% Incorrect

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• 339 Solvers

Last Solution submitted on May 02, 2025

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