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 = 242, v2 = 112.9.
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: 26.
Formula and calculation:
(v1 - v2) / v1 =
(- 76 - 26) / - 76 =
-102 / - 76 ≈
1.342105263158 ≈
1.34
Although the absolute difference is negative: -102, the relative decrease change is positive: 1.34. 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:
(242 - 112.9)/|242| =
129.1/242 =
129.1 ÷ 242 =
129.1 ÷ 242 × 100/100 =
(129.1 × 100 ÷ 242)/100 =
(12,910 ÷ 242)/100 ≈
53.347107438017/100 =
53.347107438017% ≈
53.35%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 242 to the final, end value 112.9:
Rounded off to max. 12 decimal places ≈ 53.347107438017%
Rounded off to max. 2 decimal places ≈ 53.35%
The absolute (actual) difference
242 - 112.9 = 129.1
By what percentage has 242 decreased?
Answer: By ≈ 53.35%
By what percentage is 112.9 smaller than 242?
Answer: By ≈ 53.35%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).