A private medical clinic wants to estimate the true mean annual income of its patients.?

The clinic needs to be within $500 of the true mean. The clinic estimates that the true population standard deviation is around $2,300. If the confidence level is 95%, find the required sample size in order to meet the desired accuracy.








a. 195


b. 80


c. 82


d. 101A private medical clinic wants to estimate the true mean annual income of its patients.?
ANSWER: c. Sample Size = 82





Why??





CHOOSING CHOOSING THE SAMPLE SIZE


n = [(z-critical value * s)/B]^2





z-critical value = 1.96 (associated with 95% confidence level)


s = STANDARD DEVIATION [2300]


B = BOUND ON THE ERROR OF ESTIMATION [500]

skinny myspace