Linq-style queries on a javascript array can yield some useful results. Here we have some example data which includes name, age, salary and a few more fields for us to experiment with.
You can start by looking at the raw data to see what we're working from
You could count freelancers by title
You could group everyone by age to see our population distribution
You could sort by age or see which age group has the smallest population
You could create a really complex query that groups and selects multiple times