Question

A story on A pair of best friends, ratio and proportion had a fight

Answer 1

Answer:

Explanation:

A proportion is an equation that says that two or more ratios are equal. For instance if one package of cookies contain 20 cookies that would mean that 2 packages contain 40 cookies

201=402

A proportion is read as "x is to y as a is to b".

xy=ab

xy⋅y=ab⋅y

x⋅b=ab⋅yb

xb=ay

The products xb and ay are called cross products. The cross products of a proportion are always equal. If we want to check if two ratios form a proportion we can just check their cross products.

Example

Use cross product to determine if the two ratios form a proportion.

216,540

216=?540

216⋅16⋅40=?540⋅16⋅40

216⋅16⋅40=?540⋅16⋅40

2⋅40=?5⋅16

80=80

Here we can see that 2/16 and 5/40 are proportions since their cross products are equal.

Percent means hundredths or per hundred and is written with the symbol, %. Percent is a ratio were we compare numbers to 100 which means that 1% is 1/100.