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 = 370, v2 = - 18.6.
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: - 36.
- Choose a random positive number for the end value: 91.
Formula and calculation:
(v1 - v2) / v1 =
(- 36 - 91) / - 36 =
-127 / - 36 ≈
3.527777777778 ≈
3.53
Although the absolute difference is negative: -127, the relative decrease change is positive: 3.53. 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:
(370 - (- 18.6))/|370| =
(370 + 18.6)/|370| =
388.6/370 =
388.6 ÷ 370 =
388.6 ÷ 370 × 100/100 =
(388.6 × 100 ÷ 370)/100 =
(38,860 ÷ 370)/100 =
105.027027027027/100 =
105.027027027027% ≈
105.03%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 370 to the final, end value - 18.6:
Not rounded = 105.027027027027%
Rounded off to max. 2 decimal places ≈ 105.03%
The absolute (actual) difference
370 + 18.6 = 388.6
By what percentage has 370 decreased?
Answer: By ≈ 105.03%
By what percentage is - 18.6 smaller than 370?
Answer: By ≈ 105.03%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).