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 = 37, v2 = - 12.2.
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: - 52.
- Choose a random positive number for the end value: 31.
Formula and calculation:
(v1 - v2) / v1 =
(- 52 - 31) / - 52 =
-83 / - 52 ≈
1.596153846154 ≈
1.6
Although the absolute difference is negative: -83, the relative decrease change is positive: 1.6. 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:
(37 - (- 12.2))/|37| =
(37 + 12.2)/|37| =
49.2/37 =
49.2 ÷ 37 =
49.2 ÷ 37 × 100/100 =
(49.2 × 100 ÷ 37)/100 =
(4,920 ÷ 37)/100 ≈
132.972972972973/100 =
132.972972972973% ≈
132.97%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 37 to the final, end value - 12.2:
Rounded off to max. 12 decimal places ≈ 132.972972972973%
Rounded off to max. 2 decimal places ≈ 132.97%
The absolute (actual) difference
37 + 12.2 = 49.2
By what percentage has 37 decreased?
Answer: By ≈ 132.97%
By what percentage is - 12.2 smaller than 37?
Answer: By ≈ 132.97%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).