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 = 20.328, v2 = 7.6.
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: - 62.
- Choose a random positive number for the end value: 49.
Formula and calculation:
(v1 - v2) / v1 =
(- 62 - 49) / - 62 =
-111 / - 62 ≈
1.790322580645 ≈
1.79
Although the absolute difference is negative: -111, the relative decrease change is positive: 1.79. 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:
(20.328 - 7.6)/|20.328| =
12.728/20.328 =
12.728 ÷ 20.328 =
12.728 ÷ 20.328 × 100/100 =
(12.728 × 100 ÷ 20.328)/100 =
(1,272.8 ÷ 20.328)/100 ≈
62.613144431326/100 =
62.613144431326% ≈
62.61%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 20.328 to the final, end value 7.6:
Rounded off to max. 12 decimal places ≈ 62.613144431326%
Rounded off to max. 2 decimal places ≈ 62.61%
The absolute (actual) difference
20.328 - 7.6 = 12.728 ≈ 12.73
By what percentage has 20.328 decreased?
Answer: By ≈ 62.61%
By what percentage is 7.6 smaller than 20.328?
Answer: By ≈ 62.61%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).