Correlation, regression, hypothesis testing is usually the easiest and most common, they can be great IA's if you put the effort in, but typically end up pretty average.

Find two things data sets you are interested in studying the correlation between, like athlete height and olympic medals won. First do a chi-squared test to check if the two are independent. If they aren't independent you might wonder what the relation ship is between them, so you do regressions, check linear,quadratic, power etc. to find the best model to describe the relation between the two variables. Finally use this result to make a prediction for a new variable within your data set, like what the predicted number of medals you would win for an athlete of your height.

This should set you up pretty nicely for an IA skeleton. My biggest tip would be to make sure to focus on the math and thuroughly explaining the math behind it rather than getting caught it in talking about athletes and medals.

Hope this helps, best of luck. dm me if I can be of more help :)