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 = 34, v2 = 69.6.
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: - 17.
- Choose a random positive number for the end value: 60.
Formula and calculation:
(v1 - v2) / v1 =
(- 17 - 60) / - 17 =
-77 / - 17 ≈
4.529411764706 ≈
4.53
Although the absolute difference is negative: -77, the relative decrease change is positive: 4.53. 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:
(34 - 69.6)/|34| =
- 35.6/34 =
- 35.6 ÷ 34 =
- 35.6 ÷ 34 × 100/100 =
(- 35.6 × 100 ÷ 34)/100 =
(- 3,560 ÷ 34)/100 ≈
- 104.705882352941/100 =
- 104.705882352941% ≈
- 104.71%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 34 to the final, end value 69.6:
Rounded off to max. 12 decimal places ≈ - 104.705882352941%
Rounded off to max. 2 decimal places ≈ - 104.71%
The absolute (actual) difference
34 - 69.6 = - 35.6
By what percentage has 34 decreased?
Answer: By ≈ - 104.71%
By what percentage is 69.6 smaller than 34?
Answer: By ≈ - 104.71%
The relative percent decrease change is negative,
so in this case we really have a relative percent increase instead
(the value goes up).