**Introduction for percentage of decrease between to numbers:**

Percent difference is defined as a difference between two numbers which is the difference between them as a percent of one of them. It is frequently used as a quantitative indicator of quality assurance and quality control for repeated measurements.

Percentage difference is related to another comparison method called percentage error. Percent difference is dissimilar in that the neither of the two values are the accepted or the actual value; they are both an experimental value determined by two unusual techniques but describing the similar intentional value.

The percent difference between the two experimental values, x1 and x2 that can be calculated by dividing the absolute difference between the two values by the average value of the same two numbers as shown below.

Percentage difference = mod(2(x1-x2) (x1+x2))*100.

The standard form of calculating the percentage decrease involves using the absolute function that imposed on the difference between the experimental (measured) and theoretical (accepted) values. Then

Percentage decrease =(mod(experimental- theoretical)/mod(theoretical))*100.

**Example problems for the** **percentage of difference between two numbers:**

**Example 1:**

A number 30 is decreased to 12 . Find the percentage of decrease between the two numbers.

**Solution:**

Percentage decrease = (mod(experimental- theoretical)/mod(theoretical))*100.

= mod(12 – 30)*100/mod(30)

**
= **
18 *100/30.

**
= ** 3*6*10*10/3*10.

= 6*10.

= 60%.

Hence the percentage of decrease between two numbers are 60%.

**Example2:**

A number 480 is decreased to 60 . Find the percentage of decrease between the two numbers.

**Solution:**

Percentage decrease = (mod(experimental- theoretical)/mod(theoretical))*100.

= mod(60 – 480)*100/mod(480)

**
= **
420 *100/480.

**
= ** 7*60*100/8*60.

= 700/8.

= 87.5%.

Hence the percentage of decrease between two numbers are 87.5%.

**Example 3:**

Jhonson has invested 15000 in a buisness and he lost 3000 from his buisness .what is the percentage of decrease in his initial amount.

**Solution:**

Percentage decrease = (mod(experimental- theoretical)/mod(theoretical))*100.

Experimental value = 15000-3000

= 12000

Percentage decrease = mod(12000 – 15000)*100/mod(15000)

**
= **
3000 *100/15000.

**
= ** 3000 *100/3000*5.

= 100/5.

= 20%.

Hence the percentage of decrease is 20%.

**Problem 1:**

A number 90 is decreased to 15 . Find the percentage of decrease between the two numbers.

**Solution**:83.33%

**Problem 2:**

A number 450 is decreased to 75 . Find the percentage of decrease between the two numbers.

**Solution**:83.33%

**Problem 3:**

Pollard has initial amount about 1800 he rented 300 from Mike and he invented the total in a buisness and he lost $390 from his buisness .what is the percentage of decrease in his initial amount.

**Solution**:81.42%