Use the given information to find the minimum sample size required to estimate an unknown population mean.
how many weeks of data must be randomly sampled to estimate the mean weekly sales of a new line of athletic footwear? we want 99% confidence that the sample mean is within $200 of the population mean, and the population standard deviation is known to be $1,100.
a)117
b)82
c)201
d)165

C) 201

Step-by-step explanation:

Margin of error = critical value × standard error

ME = CV × SE

Assuming n > 30, we can approximate CV with a normal distribution.  At P = 99%, CV = 2.576.

SE = σ / √n

SE = 1100 / √n

Therefore:

200 = 2.576 × 1100 / √n

n = 201

so far i think you have the right thing going for you just remember soh cah toh

step-by-step explanation:

sine over hypotenuse

cosine   equals adjacent

tangent over hypotenuse