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 = 19, v2 = 572.1.
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: - 18.
- Choose a random positive number for the end value: 31.
Formula and calculation:
(v1 - v2) / v1 =
(- 18 - 31) / - 18 =
-49 / - 18 ≈
2.722222222222 ≈
2.72
Although the absolute difference is negative: -49, the relative decrease change is positive: 2.72. 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:
(19 - 572.1)/|19| =
- 553.1/19 =
- 553.1 ÷ 19 =
- 553.1 ÷ 19 × 100/100 =
(- 553.1 × 100 ÷ 19)/100 =
(- 55,310 ÷ 19)/100 ≈
- 2,911.052631578947/100 =
- 2,911.052631578947% ≈
- 2,911.05%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 19 to the final, end value 572.1:
Rounded off to max. 12 decimal places ≈ - 2,911.052631578947%
Rounded off to max. 2 decimal places ≈ - 2,911.05%
The absolute (actual) difference
19 - 572.1 = - 553.1
By what percentage has 19 decreased?
Answer: By ≈ - 2,911.05%
By what percentage is 572.1 smaller than 19?
Answer: By ≈ - 2,911.05%
The relative percent decrease change is negative,
so in this case we really have a relative percent increase instead
(the value goes up).