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Read It Purpose that the marginal revenue for a product is given by -50 MR = + 50 (2x + 1)2 where x is the number of units and revenue is in dollars. Find the total revenue, R(x). R (X ) = Need Help? Read It Master It 8. [-/2 Points] DETAILS HARMATHAP12 12.2.051. MY NOTES ASK YOUR TEACHER PR The rate of change in data entry speed of the average student is ds/dx = 3(x + 9)/2, where x is the number of lessons the student has had and s is in entries per minute. (a) Find the data entry speed as a function of the number of lessons if the average student can complete 18 entries per minute with no lessons (x = 0). S ( X) = (b) How many entries per minute can the average student complete after 7 lessons? entries per minute Need Help? Read It Watch ItAn excellent lm with a very small advertising budget must depend largely on word-of-mouth advertising. In this case, the rate at which weekly attendance might grow can be given by dA 100 2000 _ = 2 + 3 dt (t + 10) (t+ 10) where t is the time in weeks since release and A is attendance in millions. (a) Find the function that describes weekly attendance at this film. (Assume A(0) = 0.) A(t) = (b) Find the attendance at this lm in the sixth week. (Round your answer to one decimal place.) million Need Help