Calculation Body Mass

Question

Calculating body-mass index (BMI) is a way to gauge whether a person should lose weight. Doctors recommend that body-mass index values fall between 19 and 25. The formula for Body mass index B is B=705w/h^2, where w is weight in pounds and h is height in inches. A patient is 6ft 2 in tall. What should his or her weight be to have a body mass index of 25? (Round to the nearest whole pound) 

Answer 1

Theresa:

 

Per your formula, B=(705w)/h², where w=weight in pounds and h=height in inches.

 

From the info provided, we know that B=25 and h=74 inches (6ft * 12 inches per foot + 2 inches).

 

Substituting these values in the formula, we get:  25=(705w)/(74*74)

                                                                       25=705w/5476

 

Now, solving for w, we get w=(25*5476)/705=194.18 pounds (rounded to nearest hundredth).

 

Hope this helps.

 

George T.

Answer 2

Solving for w gives:

 

w=Bxh² /705

 

Since you were given that:

B=25

h=74"

then w=25x(74²)/705= 194 lbs

 

Answer 3

 Ok:

 

h = 6ft, 2 in = 6* 12" + 2 = 74"

 

    W is unknown and has to be evaluated.

 

     750 w / 74² = 25

 

       w = (74² * 25 )/ 705 = 194.

 

    Thank you Jim . I took 750 for 705.

Answer 4

Hey Theresa -- one BMI that's easy to work with is 70" (5ft 10in)  at 140lb = 20 BMI ... 30 BMI at 70" thus 210lb ... 25 BMI "in-between" at 175lb ... every 1" change is about 1.5% => means weight must change 3% (double the ht change since h^2) ==> 6'2" is 4" or 6% change, wt change 12% or 20lb to ~195lb. CHECK: BMI = 700*200/74^2 ~ 140000/(5200+300) ~140k/55k ~28/11 ~25 ... Regards, ma'am :)

Answer 5

 

 

B=705w/h^2

Solve for w,

w = Bh^2/705 = 25(6*12+2)^2/705 = 194.2 lb <==Answer