A regression was run to determine if there is a relationship between hours of TV watched per day (x) and number of situps a person can do (y). The results of the regression were:

y=ax+b

a=-0.953

b=34.924

r²=0.605284

r=-0.778

Use this to predict the number of situps a person who watches 7.5 hours of TV can do (to one decimal place)