A1-ounce serving of cream cheese contains 9.1 grams of saturated fat. how much saturated fat is in 15 ounces of cream cheese?

136.5 g

Solution:

This question is answerd easily using the notion of proportions.

A proportion is the equivalence of two ratios.

When two magnitudes (variables) are proportional you can state equivalent ratios, and if one of the magnitudes is unknow you can solve the equation.

In this case the two ratios are:

1)

1 ounce

   9.1 g

2)

15 ounce

       x

So, the proportion is:

 1 ounce          15 ounce
=  
  9.1 g                     x

Now, you clear the x:

x = 15 ounce * 9.1 g / 1 ounce = 136.5 g.

And that is the 136.5 g

This method will permit you to solve many questions where the variables or measures are proportional.

1 ounce has 9.1 grams
15 ounces  will have 9.1 ·15 =136.5 grams of saturated fat