If there are 3 in 1500 kids who get cancer how many have cancer if there are 11,721,722 kids?

You have used 150 instead of 1500 Melody.

3 in 1500 is a ratio of diagnosed kids to healthy kids. Solve this by using a proportion.

3/1500 = x/11,721,722    x is the amount of diagnosed kids. Cross multiply.

1500x = 35,165,166        Now you have an equation. Divide both sides by 1500.

x = 23,443.444

Approximatedly 22,444 kids out of 11,721,722 are diagnosed with cancer.

$$\frac{3}{150}=\frac{x}{11721722}$$

$${\frac{{\mathtt{3}}}{{\mathtt{150}}}}{\mathtt{\,\times\,}}{\mathtt{11\,721\,722}} = {\mathtt{234\,434.44}}$$

$$x=$$ 234434.44

Our answers appear to be different by a power of 10.

The question asker can decide which answer is correct.  One of us has made a silly mistake i guess.

THIS IS WRONG - SEE ALAN'S COMMENT.

Thanks Alan,