Question

in a certain state, the number of endangered birds decreased from 780 in oneyear to 750 in the next year. What percent decrease of this endangered bird does thisrepresent? (Round your answer to two decimal places.)

Answer 1

We can calculate the percent decrease (or increase) dividing two numbers:

- The numerator is the change between the two periods: the latest state (in this case, 750 is the latest) minus the previous period state (in this case, 780). As this difference is negative (750-780=-30), there is a decrease.

- The denominator is the base case to which we compare, as this is a percent change respect to something. In this case, this number is the previous period state: 780.

Finally, we multiply by 100 to make it a percentage.

We can calculate now this as:

`\text{percent change}=(750-780)/(780)\cdot100\%=(-30)/(780)\cdot100\%=0.0385\cdot100=3.85\%`

The percent decrease is 3.85%.