The sample size (n) was found by counting the number of years that the percentage of unemployment in Maine was measured in the data. The sample mean () was found by computing "=average()" for the percentage of unemployment in google sheets. The standard deviation () was found by computing "=stdev.s()" for the percentage of unemployment, also in google sheets. For this data set, I've decided to use a 95% level of confidence. The alpha level () for a 95% confidence level is 0.05. Degrees of freedom (df) is equal to n-1. The margin of error () is calculated computing =confidence.t(alpha, standard deviation, sample size) in google sheets.