The Weather Underground reported that the mean amount of summer rainfall for the northeastern US in 2019 was 11.52 inches. In order to estimate the average rainfall in 2020, ten cities in the northeast are randomly selected and the rainfall amount in each city is recorded. Which confidence interval would be most appropriate to do here? One mean (sigma known) One mean (sigma unknown) Mean of differences, using dependent samples (paired data). Difference of two means (independent samples) One proportion. Difference of two proportions Slope of the regression line