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 = 1,158, v2 = 1,079.5.
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: - 2.
- Choose a random positive number for the end value: 93.
Formula and calculation:
(v1 - v2) / v1 =
(- 2 - 93) / - 2 =
-95 / - 2 =
47.5
Although the absolute difference is negative: -95, the relative decrease change is positive: 47.5. 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:
(1,158 - 1,079.5)/|1,158| =
78.5/1,158 =
78.5 ÷ 1,158 =
78.5 ÷ 1,158 × 100/100 =
(78.5 × 100 ÷ 1,158)/100 =
(7,850 ÷ 1,158)/100 ≈
6.778929188256/100 =
6.778929188256% ≈
6.78%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 1,158 to the final, end value 1,079.5:
Rounded off to max. 12 decimal places ≈ 6.778929188256%
Rounded off to max. 2 decimal places ≈ 6.78%
The absolute (actual) difference
1,158 - 1,079.5 = 78.5
By what percentage has 1,158 decreased?
Answer: By ≈ 6.78%
By what percentage is 1,079.5 smaller than 1,158?
Answer: By ≈ 6.78%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).