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 = 300, v2 = 43.4.
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: - 37.
- Choose a random positive number for the end value: 61.
Formula and calculation:
(v1 - v2) / v1 =
(- 37 - 61) / - 37 =
-98 / - 37 ≈
2.648648648649 ≈
2.65
Although the absolute difference is negative: -98, the relative decrease change is positive: 2.65. 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:
(300 - 43.4)/|300| =
256.6/300 =
256.6 ÷ 300 =
256.6 ÷ 300 × 100/100 =
(256.6 × 100 ÷ 300)/100 =
(25,660 ÷ 300)/100 ≈
85.533333333333/100 =
85.533333333333% ≈
85.53%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 300 to the final, end value 43.4:
Rounded off to max. 12 decimal places ≈ 85.533333333333%
Rounded off to max. 2 decimal places ≈ 85.53%
The absolute (actual) difference
300 - 43.4 = 256.6
By what percentage has 300 decreased?
Answer: By ≈ 85.53%
By what percentage is 43.4 smaller than 300?
Answer: By ≈ 85.53%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).