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 = 6.91, v2 = - 3.
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: - 58.
- Choose a random positive number for the end value: 61.
Formula and calculation:
(v1 - v2) / v1 =
(- 58 - 61) / - 58 =
-119 / - 58 =
2.051724137931 ≈
2.05
Although the absolute difference is negative: -119, the relative decrease change is positive: 2.05. 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:
(6.91 - (- 3))/|6.91| =
(6.91 + 3)/|6.91| =
9.91/6.91 =
9.91 ÷ 6.91 =
9.91 ÷ 6.91 × 100/100 =
(9.91 × 100 ÷ 6.91)/100 =
(991 ÷ 6.91)/100 ≈
143.415340086831/100 =
143.415340086831% ≈
143.42%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 6.91 to the final, end value - 3:
Rounded off to max. 12 decimal places ≈ 143.415340086831%
Rounded off to max. 2 decimal places ≈ 143.42%
The absolute (actual) difference
6.91 + 3 = 9.91
By what percentage has 6.91 decreased?
Answer: By ≈ 143.42%
By what percentage is - 3 smaller than 6.91?
Answer: By ≈ 143.42%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).