Question #e2eed

2 Answers
May 27, 2017

Marie has decreased her calorie intake by #38.1%.#

Explanation:

First, we need the amount that Marie's calorie intake has decreased

#2100-1300=800 " cal"#

Marie is eating #800# less calories than before.

Now we need to ask the question,:

"What fraction of the initial calorie intake is #800#?"

#800/2100=0.3810#

#800# calories is #0.3810# of the initial intake, so Marie is eating #0.3810# less than she used to.

To convert a fraction to a percentage, multiply by #100%#

#0.3810*100%=38.1"%"#

Marie is eating #38.1%# less calories than she used to.

May 27, 2017

#38%# decrease

Explanation:

To calculate the percentage change:

Step 1. Work out the difference between the two numbers you are comparing. New number minus old number.

#1300-2100=-800#

Step 2. Divide the difference by the old, original number. If your answer is a negative number then this is a percentage decrease. If it's positive, then it is a percent increase.

#(-800)/(2100)~~-0.38#

Step 3. Multiply by 100%. Notice negative sign doesn't just magically disappear. Rather, it gets turned into the word "decrease".

#-0.38xx100%=38%color(white)(aaa)#decrease.