Tried to put in graphing calculator but lines were not the same. Help please and thank you.

The average typing speeds S (in words per minute) of a typing student after t weeks of lessons are shown in the table. t 5 10 15 20 25 30 S 27 54 67 76 81 85 A model for the data is given by the following. 90t2 S=- t>0 60 + t- (a) Use a graphing utility to plot the data and graph the model. 120- 120- 100 100 80 80 60 40 20 O 05 10 15 20 25 30 10 15 20 25 30 120 120 100 100 BO 80 GO 60 40 20 20 05 10 15 20 25 30 O 0 5 10 15 20 25 30 (b) Does there appear to be a limiting typing speed? Yes No What is the limit? words per minute