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 = 160.25, v2 = 122.2.
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: - 46.
- Choose a random positive number for the end value: 10.
Formula and calculation:
(v1 - v2) / v1 =
(- 46 - 10) / - 46 =
-56 / - 46 ≈
1.217391304348 ≈
1.22
Although the absolute difference is negative: -56, the relative decrease change is positive: 1.22. 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:
(160.25 - 122.2)/|160.25| =
38.05/160.25 =
38.05 ÷ 160.25 =
38.05 ÷ 160.25 × 100/100 =
(38.05 × 100 ÷ 160.25)/100 =
(3,805 ÷ 160.25)/100 ≈
23.744149765991/100 =
23.744149765991% ≈
23.74%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 160.25 to the final, end value 122.2:
Rounded off to max. 12 decimal places ≈ 23.744149765991%
Rounded off to max. 2 decimal places ≈ 23.74%
The absolute (actual) difference
160.25 - 122.2 = 38.05
By what percentage has 160.25 decreased?
Answer: By ≈ 23.74%
By what percentage is 122.2 smaller than 160.25?
Answer: By ≈ 23.74%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).