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 = 496, v2 = 126.9.
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: 40.
Formula and calculation:
(v1 - v2) / v1 =
(- 43 - 40) / - 43 =
-83 / - 43 ≈
1.93023255814 ≈
1.93
Although the absolute difference is negative: -83, the relative decrease change is positive: 1.93. 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:
(496 - 126.9)/|496| =
369.1/496 =
369.1 ÷ 496 =
369.1 ÷ 496 × 100/100 =
(369.1 × 100 ÷ 496)/100 =
(36,910 ÷ 496)/100 ≈
74.415322580645/100 =
74.415322580645% ≈
74.42%
(Rounded off to max. 2 decimal places)
The relative percent decrease change
from the original, initial value 496 to the final, end value 126.9:
Rounded off to max. 12 decimal places ≈ 74.415322580645%
Rounded off to max. 2 decimal places ≈ 74.42%
The absolute (actual) difference
496 - 126.9 = 369.1
By what percentage has 496 decreased?
Answer: By ≈ 74.42%
By what percentage is 126.9 smaller than 496?
Answer: By ≈ 74.42%
The relative percent decrease change is positive,
so we really have a relative percent decrease
(the value goes down).