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 = 289, v2 = 100.9.
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: - 26.
- Choose a random positive number for the end value: 81.
Formula and calculation:
(v1 - v2) / v1 =
(- 26 - 81) / - 26 =
-107 / - 26 ≈
4.115384615385 ≈
4.12
Although the absolute difference is negative: -107, the relative decrease change is positive: 4.12. 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:
(289 - 100.9)/|289| =
188.1/289 =
188.1 ÷ 289 =
188.1 ÷ 289 × 100/100 =
(188.1 × 100 ÷ 289)/100 =
(18,810 ÷ 289)/100 ≈
65.086505190311/100 =
65.086505190311% ≈
65.09%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 289 to the final, end value 100.9:
Rounded off to max. 12 decimal places ≈ 65.086505190311%
Rounded off to max. 2 decimal places ≈ 65.09%
The absolute (actual) difference
289 - 100.9 = 188.1
By what percentage has 289 decreased?
Answer: By ≈ 65.09%
By what percentage is 100.9 smaller than 289?
Answer: By ≈ 65.09%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).