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 = 579, v2 = 527.8.
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: - 64.
- Choose a random positive number for the end value: 25.
Formula and calculation:
(v1 - v2) / v1 =
(- 64 - 25) / - 64 =
-89 / - 64 =
1.390625 ≈
1.39
Although the absolute difference is negative: -89, the relative decrease change is positive: 1.39. 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:
(579 - 527.8)/|579| =
51.2/579 =
51.2 ÷ 579 =
51.2 ÷ 579 × 100/100 =
(51.2 × 100 ÷ 579)/100 =
(5,120 ÷ 579)/100 ≈
8.842832469775/100 =
8.842832469775% ≈
8.84%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 579 to the final, end value 527.8:
Rounded off to max. 12 decimal places ≈ 8.842832469775%
Rounded off to max. 2 decimal places ≈ 8.84%
The absolute (actual) difference
579 - 527.8 = 51.2
By what percentage has 579 decreased?
Answer: By ≈ 8.84%
By what percentage is 527.8 smaller than 579?
Answer: By ≈ 8.84%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).