(03.08 MC) Heidi is preparing for the national gymnastics c…

(03.08 MC) Heidi is preparing for the national gymnastics competition. The table shows the number of hours Heidi spent preparing for a gymnastics competition over a period of five months: Month 1 2 3 4 5 Hours 2 3.5 5 6.5 8 Did Heidi increase the number of hours of practice linearly or exponentially?