answer all plis. a until c

1. It is known that the cellular phone subscriber data of a provider is as follows: (SCORE 15) Year 2010 2011 2012 2013 2014 2015 Customer (Million 5.2 6.2 6.8 7.5 8.9 9.2 People) a. Draw the data. b. Determine the linear trend function model for the cellular's periodic data. c. Calculate the number of customers in 2021