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 = 204, v2 = 181.6.
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: - 42.
- Choose a random positive number for the end value: 9.
Formula and calculation:
(v1 - v2) / v1 =
(- 42 - 9) / - 42 =
-51 / - 42 ≈
1.214285714286 ≈
1.21
Although the absolute difference is negative: -51, the relative decrease change is positive: 1.21. 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:
(204 - 181.6)/|204| =
22.4/204 =
22.4 ÷ 204 =
22.4 ÷ 204 × 100/100 =
(22.4 × 100 ÷ 204)/100 =
(2,240 ÷ 204)/100 ≈
10.980392156863/100 =
10.980392156863% ≈
10.98%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 204 to the final, end value 181.6:
Rounded off to max. 12 decimal places ≈ 10.980392156863%
Rounded off to max. 2 decimal places ≈ 10.98%
The absolute (actual) difference
204 - 181.6 = 22.4
By what percentage has 204 decreased?
Answer: By ≈ 10.98%
By what percentage is 181.6 smaller than 204?
Answer: By ≈ 10.98%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).