What Influences the Sample Size Needed? In this exercise, we examine the effect of the value of the estimated standard deviation on determining the sample size needed. Find the sample size needed to...

What Influences the Sample Size Needed?



In this exercise, we examine the effect of the value of the estimated standard deviation on determining the sample size needed.


Find the sample size needed to give, with 90% confidence, a margin of error within ±3, if the estimated standard deviation is σ˜=70. If the estimated standard deviation is σ˜=40. If the estimated standard deviation is σ˜=10.


Round your answers up to the nearest integer.