Question 4. (total: 4 points) (a) (3 points)The size of population of Bacillus subtilis ( in average number per petri dish ) introduced to a new nutrient can be described in the short term by the function N(t) = 50e4' + 300e3t where 0 2 t S 1 is measured in hours. At what time in the interval t 6 [0,1] is the population the largest? the smallest? (b) (1 points) Between time 0 and 1, the absolute minimum average population per dish is attained when t = the absolute maximum average population per dish is attained when t =