Quarter Year Nr. Of Clients 2015 433 Qtrz 2015 425 2015 421 mm 2015 504 2016 493 Qtr2 2016 515 2016 502 Qtr4 2016 551 2017 522 0.tr2 2017 595 2017 564 . Qtr4 2017 636 2013 622 2018 662 2013 677 2013 733 a) Calculate the multiple linear regression equation using quarterly data as dummy variables. (M) b) Interpret each slope and the intercept in the multiple linear regression equation from part 6). Calculate a 90% condence interval for each variable slope and assess whether it is statistically signicant. (5 marks) c) Create a forecast for 2019 and 2020