Monthly sales of a particular personal computer are expected to decline at the following rate of s'(t) computers per month, where t is time in months and s(t) is the number of computers sold each month.

s'(t)= -30t^(2/3)

the company plans to stop manufacturing this computer when monthly sales reach 1,000 computers. if monthly sales now (t=0) are 2,440 computers, find s(t). how long will the company continue to manufacture this computer?

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

(b) suppose that consolidated power decides to use a level of significance of α = .05, and suppose a random sample of 100 temperature readings is obtained. if the sample mean of the 100 temperature readings is x⎯⎯ = 60.990, test h0 versus ha and determine whether the power plant should be shut down and the cooling system repaired. perform the hypothesis test by using a critical value and a p-value. assume σ = 5. (round your z to 2 decimal places and p-value to 4 decimal places.)

Atruck can be rented from company a $50 a day plus $0.60 per mile. company b charges $20 a day plus $0.80 per mile to rent the same truck. find the number of miles in a day at which the rental costs for company a and company b are the same