# Correlation coefficient of two variables with unequal number of data using Excel

How do I find the correlation coefficient of two variables with unequal number of data using Excel? And do I use the mean as data to calculate?

• to get correlation, your data will be paired. If the observation for one of the variables in a pair is missing, you'd normally exclude the other member from the calculation of the correlation. Mar 3 '13 at 5:11
• @Glen_b's comment indicates you will need to provide more details about your data, user21489, in order for this question to be answerable.
– whuber
Mar 3 '13 at 18:49

A correlation coefficient requires that for every x-value there be a y-value ... otherwise, how should I know how much value of y to attribute to x? For example, if you're trying to determine how much height correlates with age, you need a collection of heights and ages. Knowing that a person is 5'5" tall doesn't help at all if you don't know how old that person is.

Do you mean that you have several y values for each of your x values? Like

5-year olds: 36", 37" 38"

6-year olds: 37", 39", 40" ... ?

If so, make a row for each y value, and include its corresponding x-value:

Age | Height

5 | 36

5 | 37

5 | 38

6 | 37

6 | 39

6 | 40

And then you can use CORREL()