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 = 4.7, v2 = - 29.4.
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: - 28.
- Choose a random positive number for the end value: 40.
Formula and calculation:
(v1 - v2) / v1 =
(- 28 - 40) / - 28 =
-68 / - 28 ≈
2.428571428571 ≈
2.43
Although the absolute difference is negative: -68, the relative decrease change is positive: 2.43. 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:
(4.7 - (- 29.4))/|4.7| =
(4.7 + 29.4)/|4.7| =
34.1/4.7 =
34.1 ÷ 4.7 =
34.1 ÷ 4.7 × 100/100 =
(34.1 × 100 ÷ 4.7)/100 =
(3,410 ÷ 4.7)/100 =
725.531914893617/100 =
725.531914893617% ≈
725.53%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 4.7 to the final, end value - 29.4:
Not rounded = 725.531914893617%
Rounded off to max. 2 decimal places ≈ 725.53%
The absolute (actual) difference
4.7 + 29.4 = 34.1
By what percentage has 4.7 decreased?
Answer: By ≈ 725.53%
By what percentage is - 29.4 smaller than 4.7?
Answer: By ≈ 725.53%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).