WORD PROBLEM

Question

IF THERE WERE ABOUT 200 REGISTERED CARS FOR EVERY 1.000 PEOPLE, WHAT WOULD BE A GOOD ESTIMATE FOR THE NUMBER OF REGISTERED CARS IF THE POPULATION IS 13,274,782?

Answer 1

13,274,782 people is about 13,000,000 people

This is 13,000 1000's

13,000*200=2,600,000 (2*13 with 5 0's)

If you want to be a little more accurate...

13,274,782 people is about 13,250,000 people

This is 13,250 1000's

13,250*200=2,650,000 (1325*2 with 3 0's), or...

13,274,782 people is about 13 1/4 million people or 13 1/4 thousand thousands

(13 1/4)*200=13*200+(1/4)*200=2600+50=2650 for 13 1/4 thousand people but we have 13 1/4 1000 1000s, so we multiply 2650 by 1000 to get 2,650,000

Answer 2

This is a perfect application of a proportion:

 

   200 cars                  x cars

------------------  =  ---------------------------

1000 people        13,274,782 people

 

Cross multiply and solve for x.

 

-----------------

 

You could also solve it by determining the unit rate:

 

200 cars/1000 people = 0.2 cars/person

 

(13,274.782 people)*(0.2 cars per person) = __________