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 = 38.84, v2 = 23.1.
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: - 58.
- Choose a random positive number for the end value: 65.
Formula and calculation:
(v1 - v2) / v1 =
(- 58 - 65) / - 58 =
-123 / - 58 ≈
2.120689655172 ≈
2.12
Although the absolute difference is negative: -123, the relative decrease change is positive: 2.12. 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:
(38.84 - 23.1)/|38.84| =
15.74/38.84 =
15.74 ÷ 38.84 =
15.74 ÷ 38.84 × 100/100 =
(15.74 × 100 ÷ 38.84)/100 =
(1,574 ÷ 38.84)/100 ≈
40.525231719876/100 =
40.525231719876% ≈
40.53%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 38.84 to the final, end value 23.1:
Rounded off to max. 12 decimal places ≈ 40.525231719876%
Rounded off to max. 2 decimal places ≈ 40.53%
The absolute (actual) difference
38.84 - 23.1 = 15.74
By what percentage has 38.84 decreased?
Answer: By ≈ 40.53%
By what percentage is 23.1 smaller than 38.84?
Answer: By ≈ 40.53%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).