a. 120, 190b. 7,409,298c. 16, 166, 019d. 352, 331, 004

The population of a state is declining at a rate of 2.6% annually.
Current population = 11 million
Population in 15 years?
We can use the exponential decay model to find the population after 15 years.
[tex]y=a\cdot(1-r)^t[/tex]Where a is the initial/current population, r is the decay rate in decimal, and t is the number of years,
Let us substitute the given values into the above formula
[tex]\begin{gathered} y=a\cdot(1-r)^t \\ y=11,000,000\cdot(1-0.026)^{15} \\ y=11,000,000\cdot(0.974)^{15} \\ y=7,409,297.59 \\ y=7,409,298 \end{gathered}[/tex]Therefore, the population of the state in 15 years is predicted to be 7,409,298
Option b is the correct answer.