Need a little help with this problem

Identify the type of observational study described. a statistical analyst obtains data about ankle injuries by examining a hospital's records from the past 3 years. cross-sectional retrospective prospective

Mr.walker is looking at the fundraiser totals for the last five years , how does the mean of the totals compare to the median?

What is the length of the segment, endpoints of which are intersections of parabolas y=x^2− 11/4 x− 7/4 and y=− 7 /8 x^2+x+ 31/8 ?