12.Some people are surprised when comparing the FEV for smokers and non-smokers. However, these two groups should not be directly compared. Look at the two data sets and identify at least one confounding factor that might impact the FEV, aside from smoker status. Briefly explain why this factor needs to be controlled before comparing the two groups

Amountain climber starts a climb at an elevation of 453 feet above sea level at his first rest stop he has climbed 162 feet and by his second rest stop he has climbed another 207 feet its getting late in the day so the climber starts his way down if the climber desends 285 feet how much does he need to ascend or descend to return to the original starting point

Simplify 1/3 12x - 6 a. -2x-1 b.-2x-8 c.-x+4 d.3x+10 e. 4x-2

Which verbal expression best describes the algebraic expression 3x ÷ 5? the quotient of three times some number and five the product of some number and five divided by three the quotient of three and some number times five the sum of three and some number divided by five