Answer
Mildly obese people: between 239-507 minutes
Lean people: between 312-740 minutes
Work Step by Step
Mildly obese:
$(x - 373)/67 = 2$
$(x - 373) = 134$
$ x = 507$
$(x - 373)/67 = -2$
$(x - 373) = -134$
$ x = 239$
Lean:
$(x - 526)/107 = 2$
$(x - 526) = 214$
$ x = 740$
$(x - 526)/107 = -2$
$(x - 526) = -214$
$ x = 312$
