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 = 10.92, v2 = 5.7.
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: - 43.
- Choose a random positive number for the end value: 56.
Formula and calculation:
(v1 - v2) / v1 =
(- 43 - 56) / - 43 =
-99 / - 43 ≈
2.302325581395 ≈
2.3
Although the absolute difference is negative: -99, the relative decrease change is positive: 2.3. 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:
(10.92 - 5.7)/|10.92| =
5.22/10.92 =
5.22 ÷ 10.92 =
5.22 ÷ 10.92 × 100/100 =
(5.22 × 100 ÷ 10.92)/100 =
(522 ÷ 10.92)/100 ≈
47.802197802198/100 =
47.802197802198% ≈
47.8%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 10.92 to the final, end value 5.7:
Rounded off to max. 12 decimal places ≈ 47.802197802198%
Rounded off to max. 2 decimal places ≈ 47.8%
The absolute (actual) difference
10.92 - 5.7 = 5.22
By what percentage has 10.92 decreased?
Answer: By ≈ 47.8%
By what percentage is 5.7 smaller than 10.92?
Answer: By ≈ 47.8%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).