1. The amounts (in ounces) of juice in eight randomly selected juice bottles are:
15.4 15.7 15.2 15.8 15.8 15.4 15.0 15.6
Assuming the population of amounts in juice bottles is known to be normally distributed, create a 95% confidence interval estimate for , the mean amount of juice in all bottles.
You will be asked to identify x-bar, s, , df, t, E and the confidence interval.
2. Previous studies have indicated the standard deviation of annual earnings for college students is $850. How large a sample would need to be taken to estimate the mean for college students' annual earnings to within $200 with 99% confidence?
3. A researcher is interested in estimating the proportion of voters who favor a tax on e-commerce. How large a sample would she need to collect to estimate this proportion to within 5% with 95% accuracy?