What measure is used to compare 2 data sets??

Various measures are used to compare 2 data sets. For example, the mean (average).

Here is one.

Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√n

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability.

The measure commonly used to compare two data sets is called the "correlation coefficient." The correlation coefficient quantifies the strength and direction of the linear relationship between two variables. It ranges between -1 and +1, where -1 indicates a perfect negative relationship, +1 indicates a perfect positive relationship, and 0 indicates no linear relationship.

To calculate the correlation coefficient, you need two sets of paired data. Let's label one set as X and the other as Y. Here's the step-by-step process:

1. Calculate the mean (average) for both X and Y.
2. Calculate the difference between each X value and its mean, and the difference between each Y value and its mean.
3. Multiply each pair of differences from step 2 together.
4. Sum up all the products from step 3.
5. Calculate the standard deviation for X and Y.
6. Multiply the standard deviation of X by the standard deviation of Y.
7. Divide the sum from step 4 by the result of step 6.
8. The resulting value is the correlation coefficient.

If you are using software like Microsoft Excel or statistical packages like Python's pandas or R, you can simply use the built-in functions to calculate the correlation coefficient. This simplifies the process and saves time compared to manually performing the calculations.