1. Define a population of people or things that are of interest to you.

2. Define two quantitative variables that could be observed or measured from a sample of your population.

3. Describe the population and the two quantitative variables, including any units of measurement.

4. Explain whether you would expect a positive, a negative, or no correlation between these two variables and why. Be specific.

Example:

My population will be all California state and regional parks. Two quantitative variables that I could observe about each park are

2. total length of all hiking trails in the park, in miles
4. size of the park, in acres

The size of the park would be the explanatory variable and the miles of hiking trails would be the response variable and I would expect there to be a positive correlation. Larger parks have more space for hiking and smaller parks have less space for hiking, so as the size of the park increases, generally so do the miles of hiking trails. The correlation may not be very strong though since some parks may be very large, but not contain established hiking trails. Parks like this would be unusual and cause the correlation to be weaker.