4. A student buys a movie to watch on her phone, but she's worried about the amount of storage space downloading it will take up. She starts the download and
notices it will download at a constant rate. After 3 minutes, she checks her phone
and sees that she has 2,345 MB of space available. She checks her phone after 7
minutes and notices that she now has 2,105 MB of space available.
(a) How many MB of available storage are being filled by the movie per minute?