Can someone help me answer this question? Also, can you please explain it? Thank you!

Okay so you a chart with increments of 5 years between each recorded population. Each 5 years the population decreases more than the previous 5 years until you get to 2010 where it had decreased more between 2005 than it did by 2010. This means the population does not decrease at a certain percentage or by a specific equation. It is more random but has the common pattern that it decreases. Guirllimo basically has his own equation where he thinks he can predict the what the population would be at any given time after the year 1990. In his equation you can test it out where the t stand for years after 1990. They want to know what the population would be after 5 years according to his equation. To do this you replace t by 5 which is the years after 1990. So -26x5+5649= guirllimos estimated population . -26x5= -130. -130+5649= 5519. 5519 is guirllimos estimated number of what the population would be according to his equation. According to the data he recorded the actual data population was 5530. According to his calculation he was only off the actual amount by 11 people. This is a close estimate but like I said the population decreases by not by any specific percentage or equation. Even tho this is true his equation seems to be within 50 people of a difference than what the actual answer would be. This is pretty good given the population is more at a random rate than a controlled rate.