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 = 0.16, v2 = 542.8.
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: - 21.
- Choose a random positive number for the end value: 90.
Formula and calculation:
(v1 - v2) / v1 =
(- 21 - 90) / - 21 =
-111 / - 21 ≈
5.285714285714 ≈
5.29
Although the absolute difference is negative: -111, the relative decrease change is positive: 5.29. 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:
(0.16 - 542.8)/|0.16| =
- 542.64/0.16 =
- 542.64 ÷ 0.16 =
- 542.64 ÷ 0.16 × 100/100 =
(- 542.64 × 100 ÷ 0.16)/100 =
(- 54,264 ÷ 0.16)/100 =
- 339,150/100 =
- 339,150%
The relative percent decrease change
from the original, initial value 0.16 to the final, end value 542.8:
= - 339,150%
The absolute (actual) difference
0.16 - 542.8 = - 542.64
By what percentage has 0.16 decreased?
Answer: By - 339,150%
By what percentage is 542.8 smaller than 0.16?
Answer: By - 339,150%
The relative percent decrease change is negative,
so in this case we really have a relative percent increase instead
(the value goes up).