A population of rodents increases exponentially at a rate of 7.5% per year.

What is the equivalent monthly rate to the nearest hundredth of a percent?

0.03%

0.60%

0.62%

0.81%

A population of butterflies decreases exponentially at a rate of 18.3% per year.

What is the equivalent monthly rate to the nearest hundredth of a percent?

1.27%

1.41%

1.53%

1.67%

1. the answer is "0.62%".

We can calculate this as;

Rate = 7.5% per year

there are 12 months in a year so,

= 7.5 / 100 x 1/12

=0.075 x 1/12

= 0.00625

for percentage multiply it with 100,

= 0.00625 x 100

=0.625% = 0.62%

2. the answer is "1.53%".

We can calculate this as;

Rate = 18.3% per year

there are 12 months in a year so,

= 18.3 / 100 x 1/12

=0.183 x 1/12

= 0.01525

for percentage multiply it with 100,

= 0.01525 x 100

=1.525% = 1.53%