The annual sales (in millions of dollars) for Starbucks Corporation from 2001 to 2006 can be modelled by: = 500.7 + 161.52 n , n = 1, 2, 3, 4, … … …
where represents the year, with n = 1 corresponding to 1981.
Find the total sales from 1981 (inclusive) until 2021 (inclusive).