The bat population in a certain Midwestern county was 260,000 in 2012, and the observed doubling time for the population is 32 years. (a) Find an exponential model n(t) = no2wa 2t/ for the population t years after 2012. n (t ) = (b) Find an exponential model n(t) = noe" for the population t years after 2012. (Round your r value to four decimal places.) n (t ) = (c) Sketch a graph of the population at time t. n(t) n(t) 1400000 1400000 1200000 1200000 1000000 1000000 800000 800000 600000 600000 400000 400000 200000 200000 10 20 30 40 50 60 O 10 20 30 40 50 60 n(t) n(t) 1400000 1400000 1200000 1200000 1000000 1000000 800000 800000 600000 600000 400000 400000 200000 200000 10 20 30 40 50 60 10 20 30 40 50 60 (d) Estimate how long it takes the population to reach 2 million. (Round your answer to two decimal places.) yr