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 = 114, v2 = 97.1.
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: - 76.
- Choose a random positive number for the end value: 71.
Formula and calculation:
(v1 - v2) / v1 =
(- 76 - 71) / - 76 =
-147 / - 76 ≈
1.934210526316 ≈
1.93
Although the absolute difference is negative: -147, the relative decrease change is positive: 1.93. 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:
(114 - 97.1)/|114| =
16.9/114 =
16.9 ÷ 114 =
16.9 ÷ 114 × 100/100 =
(16.9 × 100 ÷ 114)/100 =
(1,690 ÷ 114)/100 ≈
14.824561403509/100 =
14.824561403509% ≈
14.82%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 114 to the final, end value 97.1:
Rounded off to max. 12 decimal places ≈ 14.824561403509%
Rounded off to max. 2 decimal places ≈ 14.82%
The absolute (actual) difference
114 - 97.1 = 16.9
By what percentage has 114 decreased?
Answer: By ≈ 14.82%
By what percentage is 97.1 smaller than 114?
Answer: By ≈ 14.82%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).