Instructions
Calculate the Difference Between Two Numbers
1Write the following equation:
Delta = 42,498.21 - 20,172.11
This equation computes the delta between two numbers. The first value is the average salary a U.S. worker earned in 2012. The second value is the average wage in 1990.
2
Subtract the second number from the first number to obtain the delta, as shown below:
22,326.1 = 42,498.21 - 20,172.11
The value 22,326.1 represents the difference in average wages between 2012 and 1990.
3
Write the equation shown below:
Delta = 20,172.11 - 42,498.21
Solve this equation for delta and you get -22,326.1. When the delta is negative, that simply indicates the second number was larger than the first.
Calculate Delta Percentage
1Write the equation shown below:
Percentage Change = ((NewValue - OldValue)/OldValue)) * 100
This equation computes the percentage change between an old value and a new value.
2
Replace NewValue with 119,600, the median value for a home in 2000. Replace OldValue with 30,600, the median home value in 1940. The equation will appear as follows:
Percentage Change = ((119.600 - 30,600)/30,600)) * 100
Solve the equation to obtain 290.8, the percentage by which median home prices changed between 1940 and 2000.
3
Solve the equation to obtain 290.8, the percentage by which median home prices changed between 1940 and 2000.
4
Write the percentage change equation again, as shown below:
Percentage Change = ((NewValue - OldValue)/OldValue)) * 100
5
Replace NewValue with 3.82, the February 1996 rainfall amount in Atlanta, GA. Replace OldValue with 8.26, the January rainfall amount for the same year and location. Your equation will look like this:
Percentage Change = ((3.82 - 8.26/8.26)) * 100
Solve the equation to get a percentage change value of -53.7. Because this value is negative, the change represents a decrease between the old value and the new value.