It looks like you had some of the numbers correct, but you just labeled it and rounded it incorrectly, and the teacher gave you super partial credit for it.
For my work, I'm assuming that side A is opposite of angle A and side B is opposite of angle B, etc...
As we already have the model that describes the change of the population in Italy in terms of the years that have elapsed, we only have to replace the conditions that are requested in that equation.
Therefore to find the population of Italy in the year 2000 (t = 10 years) substitute t = 10 in the equation and have:
million people
To find the population of Italy in 2008 (t = 18 years)
substitute t = 18 in the equation and have:
million people
To predict the population in Italy for 2015 and 2020 with this model, we substitute in the equation t = 25 and t = 30
t = 25
million people
t = 30
million people