A different sample of size n=20 produced a sample mean of 31.08% and a sample standard deviation of 5.48%. Use these values to calculate a 90% confidence interval (without the use of statistical technology) for the national mean percent of low-income working families. Please show all calculations and provide the upper and lower limits that make up the confidence interval. (Round the limits to two decimal places.).

9. Using what you know about confidence intervals, what would be the effect of taking a sample of size n=50? Include why you know this to be the case.