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 = 684, v2 = 131.9.
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: - 52.
- Choose a random positive number for the end value: 89.
Formula and calculation:
(v1 - v2) / v1 =
(- 52 - 89) / - 52 =
-141 / - 52 ≈
2.711538461538 ≈
2.71
Although the absolute difference is negative: -141, the relative decrease change is positive: 2.71. 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:
(684 - 131.9)/|684| =
552.1/684 =
552.1 ÷ 684 =
552.1 ÷ 684 × 100/100 =
(552.1 × 100 ÷ 684)/100 =
(55,210 ÷ 684)/100 ≈
80.716374269006/100 =
80.716374269006% ≈
80.72%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 684 to the final, end value 131.9:
Rounded off to max. 12 decimal places ≈ 80.716374269006%
Rounded off to max. 2 decimal places ≈ 80.72%
The absolute (actual) difference
684 - 131.9 = 552.1
By what percentage has 684 decreased?
Answer: By ≈ 80.72%
By what percentage is 131.9 smaller than 684?
Answer: By ≈ 80.72%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).