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 = 325, v2 = 69.4.
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: - 76.
- Choose a random positive number for the end value: 34.
Formula and calculation:
(v1 - v2) / v1 =
(- 76 - 34) / - 76 =
-110 / - 76 ≈
1.447368421053 ≈
1.45
Although the absolute difference is negative: -110, the relative decrease change is positive: 1.45. 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:
(325 - 69.4)/|325| =
255.6/325 =
255.6 ÷ 325 =
255.6 ÷ 325 × 100/100 =
(255.6 × 100 ÷ 325)/100 =
(25,560 ÷ 325)/100 ≈
78.646153846154/100 =
78.646153846154% ≈
78.65%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 325 to the final, end value 69.4:
Rounded off to max. 12 decimal places ≈ 78.646153846154%
Rounded off to max. 2 decimal places ≈ 78.65%
The absolute (actual) difference
325 - 69.4 = 255.6
By what percentage has 325 decreased?
Answer: By ≈ 78.65%
By what percentage is 69.4 smaller than 325?
Answer: By ≈ 78.65%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).