So there are two variables a -- Who is greater than 40 year old (BINARY 0 or 1) b -- If they have a Luxury Car (Binary 0 or 1)
Now they have the data sum values.
- Total sample size -- 500
- Total number of people above 40 are -- 60
- Total number of people have luxury car -- 40
- Total number of people have luxury car and above 40 -- 10
NOTE: Draw a venn diagram if that helps
Compute the coefficient of the correlation between a and b?