To calculate the total number of babies born in the next 12 years using geometric sum, we need the initial number of babies born in 2015, which is 57,232.
Given that the birth rate drops 1% each year, this means the number of babies born each year will decrease by 1% of the previous year's number.
Let's denote the number of babies born in the first year after 2015 as x , then the number of babies born in the second year will be 0.99x , in the third year will be 0.99^2x , and so on.
The total number of babies born in the next 12 years will be the sum of a geometric series with 12 terms, starting with 57,232 babies and a common ratio of 0.99.
The formula for the sum of a geometric series is given by:
S = a \cdot \frac{1 - r^n}{1 - r}
where:
S is the total sum,
a is the first term,
r is the common ratio, and
n is the number of terms.
Substitute a = 57,232 , r = 0.99 , and n = 12 into the formula:
S = 57232 \cdot \frac{1 - 0.99^{12}}{1 - 0.99}
S=57232\cdot\frac{1-0.8863848717}{0.01}
S=57232\cdot\frac{0.1136151283}{0.01}
S=57232\cdot11.36151283
S=650,242.1022
Therefore, the total number of babies born in the next 12 years will be \boxed{650,242} .