If the standard deviation for a population is estimated to be 3,the level of error is set at .25,and the confidence level sought is equal to 95%,what sample size is needed for an international market research study that is examining consumer satisfaction with a product? (Assume a scale of "1 = extremely dissatisfied" and "10 = extremely satisfied")

Question

Quizplus · Accepted Answer

To calculate the sample size, we can use the following formula:

n = (z^2 * s^2) / E^2

Where: 
z = the value of the z-score corresponding to the confidence level (95% = 1.96) 
s = the estimated standard deviation (3) 
E = the level of error (0.25)

Plugging in these values:

n = (1.96^2 * 3^2) / 0.25^2 
n = 554.73

Rounding up to the nearest integer, we get a sample size of 554. Therefore, the best choice is B.

If the Standard Deviation for a Population Is Estimated to Be