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 = 59.54, v2 = 66.4.
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: - 64.
- Choose a random positive number for the end value: 19.
Formula and calculation:
(v1 - v2) / v1 =
(- 64 - 19) / - 64 =
-83 / - 64 =
1.296875 ≈
1.3
Although the absolute difference is negative: -83, the relative decrease change is positive: 1.3. 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:
(59.54 - 66.4)/|59.54| =
- 6.86/59.54 =
- 6.86 ÷ 59.54 =
- 6.86 ÷ 59.54 × 100/100 =
(- 6.86 × 100 ÷ 59.54)/100 =
(- 686 ÷ 59.54)/100 ≈
- 11.521666106819/100 =
- 11.521666106819% ≈
- 11.52%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 59.54 to the final, end value 66.4:
Rounded off to max. 12 decimal places ≈ - 11.521666106819%
Rounded off to max. 2 decimal places ≈ - 11.52%
The absolute (actual) difference
59.54 - 66.4 = - 6.86
By what percentage has 59.54 decreased?
Answer: By ≈ - 11.52%
By what percentage is 66.4 smaller than 59.54?
Answer: By ≈ - 11.52%
The relative percent decrease change is negative,
so in this case we really have a relative percent increase instead
(the value goes up).