Jodi,

You could just work with the numbers and use 2/8 = 1/4 = 4/16 so

2 miles/8 minutes = 1 miles/4 minutes = 4 miles/16 minutes

but I don't think that is what is expected. I think you are expected to convert this to say miles/hour or feet/minute or feet/second or some units other than miles/minute. For example let's convert miles/minute to miles/second. The units tell you what to do. There are 60 seconds in a minute so

Now try some other units.

Penny