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 = - 2.8, v2 = 980.4.
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: - 23.
- Choose a random positive number for the end value: 16.
Formula and calculation:
(v1 - v2) / v1 =
(- 23 - 16) / - 23 =
-39 / - 23 =
1.695652173913 ≈
1.7
Although the absolute difference is negative: -39, the relative decrease change is positive: 1.7. 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:
(- 2.8 - 980.4)/|- 2.8| =
- 983.2/2.8 =
- 983.2 ÷ 2.8 =
- 983.2 ÷ 2.8 × 100/100 =
(- 983.2 × 100 ÷ 2.8)/100 =
(- 98,320 ÷ 2.8)/100 ≈
- 35,114.285714285714/100 =
- 35,114.285714285714% ≈
- 35,114.29%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value - 2.8 to the final, end value 980.4:
Rounded off to max. 12 decimal places ≈ - 35,114.285714285714%
Rounded off to max. 2 decimal places ≈ - 35,114.29%
The absolute (actual) difference
- 2.8 - (980.4) = - 2.8 - 980.4 = - 983.2
By what percentage has - 2.8 decreased?
Answer: By ≈ - 35,114.29%
By what percentage is 980.4 smaller than - 2.8?
Answer: By ≈ - 35,114.29%
The relative percent decrease change is negative,
so in this case we really have a relative percent increase instead
(the value goes up).