Use the given information to find the minimum sample size required to estimate an unknown population mean $\mu$
-How many weeks of data must be randomly sampled to estimate the mean weekly sales of a new line of athletic footwear? We want 98% confidence that the sample mean is within $400 of the population mean, and the
Population standard deviation is known to be $1400.
A) 34
B) 82
C) 67
D) 48

Question

Quizplus · Accepted Answer

To find the minimum sample size required, we use the formula:
n = (z-score)^2 * (std. deviation)^2 / (error)^2
where 
z-score = 2.33 (from a z-table for 98% confidence)
std. deviation = $1400 
error = $400

Plugging in these values, we get:
n = (2.33)^2 * (1400)^2 / (400)^2
n = 67.07

Rounding up to the nearest integer, the minimum sample size required is 68, which is closest to option C (67).

Use the Given Information to Find the Minimum Sample Size μ\muμ

Use the Given Information to Find the Minimum Sample Size $\mu$