John is 5 feet tall and casts a 7.5-foot shadow. His older sister Jane casts a 9-foot shadow. How tall is John’s older sister, in feet?

Question

anonymous · Answer

This is a ratio problem:
$$\frac{ 5 }{ 7.5 } = \frac{ x }{ 9 }$$and now just solve for "x"

anonymous · Answer

I think the answer is 6.5, am I wrong?

anonymous · Answer

Yes, multiply both sides of the equation by 9 and you'll get your answer.

anonymous · Answer

oh, let me try.

anonymous · Answer

i am still lost :(

anonymous · Answer

np, I'll go a little further here for you.  Look again at my equation.  It becomes:$$\frac{ 9\times5 }{ 7.5 } = x$$that becomes$$\frac{ 45 }{ 7.5 } = x$$and now just simplify the left side.

anonymous · Answer

$$\frac{ 45 }{ 7.5 }$$means 45 divided by 7.5, if that helps

anonymous · Answer

WOW!!!!!! I totally  understand now. Thank you so much . I have to right this down

anonymous · Answer

Cool!  It's great when that old lightbulb goes on!

anonymous · Answer

sure is :)

anonymous · Answer

I like the way you explained it rather than my teacher