| Implicit Assumptions |
|---|
| ◻️ Confidence level is assumed to be 95% unless otherwise specified. |
The distribution for volume is normal with sample mean = 796ml and population standard deviation = 15ml.
What sample size is needed to reduce the margin of error to at most 3ml, when developing a 95% confidence interval for the mean volume for population?
ceiling(qnorm(0.975)^2*(15^2)/(3^2))| Implicit Assumptions |
|---|
| ◻️ If sample proportion is unavailable, π=0.5 is used to maximise (π(1-π)). |
| ◻️ Confidence level is assumed to be 95% unless otherwise specified. |
Determine number of voters to poll to ensure a sampling error of at most ± 2%.
ceiling(qnorm(0.975)^2*((0.5)*(1-0.5))/(0.02)^2)