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 = 10.11, v2 = 130.9.
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: - 45.
- Choose a random positive number for the end value: 69.
Formula and calculation:
(v1 - v2) / v1 =
(- 45 - 69) / - 45 =
-114 / - 45 ≈
2.533333333333 ≈
2.53
Although the absolute difference is negative: -114, the relative decrease change is positive: 2.53. 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:
(10.11 - 130.9)/|10.11| =
- 120.79/10.11 =
- 120.79 ÷ 10.11 =
- 120.79 ÷ 10.11 × 100/100 =
(- 120.79 × 100 ÷ 10.11)/100 =
(- 12,079 ÷ 10.11)/100 ≈
- 1,194.757665677547/100 =
- 1,194.757665677547% ≈
- 1,194.76%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 10.11 to the final, end value 130.9:
Rounded off to max. 12 decimal places ≈ - 1,194.757665677547%
Rounded off to max. 2 decimal places ≈ - 1,194.76%
The absolute (actual) difference
10.11 - 130.9 = - 120.79
By what percentage has 10.11 decreased?
Answer: By ≈ - 1,194.76%
By what percentage is 130.9 smaller than 10.11?
Answer: By ≈ - 1,194.76%
The relative percent decrease change is negative,
so in this case we really have a relative percent increase instead
(the value goes up).