Find an estimate of the sample size needed to obtain the specified margin of error for the 95% confidence interval of a
population mean.
-Margin of error $= 0.08$, sample standard deviation $= 1.4$
A) 35
B) 613
C) 1225
D) 98

Question

Quizplus · Accepted Answer

To find the sample size, use the formula $ n = \left( \frac{Z \cdot \sigma}{E} \right)^2 $, where $ Z $ is the Z-score for a 95% confidence level (approximately 1.96), $ \sigma $ is the sample standard deviation (1.4), and $ E $ is the margin of error (0.08). Plugging in these values gives $ n = \left( \frac{1.96 \cdot 1.4}{0.08} \right)^2 \approx 1225 $.

Find an Estimate of the Sample Size Needed to Obtain =0.08= 0.08=0.08

Find an Estimate of the Sample Size Needed to Obtain $= 0.08$