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 = 0.64, v2 = - 31.1.
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: - 22.
- Choose a random positive number for the end value: 39.
Formula and calculation:
(v1 - v2) / v1 =
(- 22 - 39) / - 22 =
-61 / - 22 ≈
2.772727272727 ≈
2.77
Although the absolute difference is negative: -61, the relative decrease change is positive: 2.77. 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:
(0.64 - (- 31.1))/|0.64| =
(0.64 + 31.1)/|0.64| =
31.74/0.64 =
31.74 ÷ 0.64 =
31.74 ÷ 0.64 × 100/100 =
(31.74 × 100 ÷ 0.64)/100 =
(3,174 ÷ 0.64)/100 =
4,959.375/100 =
4,959.375% ≈
4,959.38%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 0.64 to the final, end value - 31.1:
Not rounded = 4,959.375%
Rounded off to max. 2 decimal places ≈ 4,959.38%
The absolute (actual) difference
0.64 + 31.1 = 31.74
By what percentage has 0.64 decreased?
Answer: By ≈ 4,959.38%
By what percentage is - 31.1 smaller than 0.64?
Answer: By ≈ 4,959.38%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).