3 The following data were obtained from a tracer test to a reactor. t(s) 0 5 10 15 C (mg/dm) 0 0 5 30 au 20 10 25 5 35 0 0 0 . 1) Plot (t). 2) Find E() 3) Find the fraction of material that spends between 15 and 20 seconds in the reactor. 4) Find F(t) and the fraction of material that spends 25 seconds or less in the reactor. 5) Evaluate mean residence time. 6) Evaluate the variance. 0 5 10 15 20 25 30 35 0 5 10 15 20 25 30 35 5 10 15 20 25 30 35