The relative decrease change. Definition:
The relative decrease change is the difference in an indicator over two periods in time, v1 - v2, relative to the value of the indicator in the earlier period, v1.
- Where:
- v1 - is called the reference value (original, initial number);
- v2 - is called the new value (the end value).
- In our case: v1 = 10.23, v2 = 40.2.
The relative decrease change. Formula:
The relative decrease change =
The actual change / |v1|
(v1 - v2) / |v1| =
- Legend:
- v1 - the original number
- |v1| - the positive value of v1, |v1| >= 0. By example: |10| = 10; |-10| = 10.
- v2 - the new value
- The actual change = v1 - v2
- / - the fraction bar (division)
Why do we use |v1| in the formula instead of v1?
- Let's see what happens if we use v1 instead of |v1|:
- Choose a random negative number as the initial value: - 3.
- Choose a random positive number for the end value: 53.
Formula and calculation:
(v1 - v2) / v1 =
(- 3 - 53) / - 3 =
-56 / - 3 ≈
18.666666666667 ≈
18.67
Although the absolute difference is negative: -56, the relative decrease change is positive: 18.67. By using |v1| instead of v1, the error is corrected.
The relative percent decrease change. Detailed calculations below
By multiplying a number by the fraction 100/100,
we change only the form of the result, not the result.
- 100/100 = 100% = 100 ÷ 100 = 1.
- n × 100/100 = (n × 100)/100 = (n × 100)%, any number.
The relative percent decrease change. Formula:
The relative percent decrease change =
The relative decrease change × 100/100 =
(The relative decrease change × 100)/100 =
(The relative decrease change × 100)%
Calculate the relative percent decrease change:
(10.23 - 40.2)/|10.23| =
- 29.97/10.23 =
- 29.97 ÷ 10.23 =
- 29.97 ÷ 10.23 × 100/100 =
(- 29.97 × 100 ÷ 10.23)/100 =
(- 2,997 ÷ 10.23)/100 ≈
- 292.961876832845/100 =
- 292.961876832845% ≈
- 292.96%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 10.23 to the final, end value 40.2:
Rounded off to max. 12 decimal places ≈ - 292.961876832845%
Rounded off to max. 2 decimal places ≈ - 292.96%
The absolute (actual) difference
10.23 - 40.2 = - 29.97
By what percentage has 10.23 decreased?
Answer: By ≈ - 292.96%
By what percentage is 40.2 smaller than 10.23?
Answer: By ≈ - 292.96%
The relative percent decrease change is negative,
so in this case we really have a relative percent increase instead
(the value goes up).