Asked by Nicole
A population has a standard deviation of 15.2. How large a sample must be drawn so that a 95% confidence interval for the population mean will have a margin error equal to 3.5?
Answers
Answered by
MathGuru
Use a formula to find sample size.
Here is one:
n = [(z-value * sd)/E]^2
...where n = sample size, z-value = 1.96 for 95% confidence, sd = 15.2, E = 3.5, ^2 means squared, and * means to multiply.
Plug the values into the formula and finish the calculations. Round your answers to the next highest whole number.
I'll let you take it from here.
Here is one:
n = [(z-value * sd)/E]^2
...where n = sample size, z-value = 1.96 for 95% confidence, sd = 15.2, E = 3.5, ^2 means squared, and * means to multiply.
Plug the values into the formula and finish the calculations. Round your answers to the next highest whole number.
I'll let you take it from here.