What is the sales promotion letter?

Metro department store found that t week after the end of a sales promotion the vloume of sales was given by..?

• metro department store found that t week after the end of a sales promation the vloume of sales was given by S(t)=B+Ae^-kt (0 ≤ t ≤ 4) where B= 50,000 and is equal to the average weekly volume of sales before promotion. the sales volumes at the end of the first and third weeks were $83,515 and $65,055, respectively. assume that the sales volume is decreasing exponentially. a) find the decay constant k b) find the sales volume at the end of the fourth week.

• Answer:

  [eq 1] 83515 = 50000 + Ae^-k1 [eq 2] 65055 = 50000 + Ae^-k3 This gives us 33515 = Ae^-k 15055 = Ae^-3k Dividing the equations, we get Ae^-k / Ae^-3k = 33515 / 15055 e^2k = 33515 / 15055 2k = ln (33515 / 15055) Can you take it from there?