Because cardiac deaths appear to increase after heavy snowfall, an experiment was designed to compare cardiac demands of snow shoveling to use of using an electric snow thrower. Ten subjects cleared tracts of snow using both methods, and their maximum heart rates (beats per minute) were recorded during both activities. The results shown below were obtained: Manual snow shoveling maximum heart rates: n = 10, xbar = 175, s = 15. Electric snow thrower maximum heart rates: n = 10, xbar = 124, s = 18. Find a 95% confidence interval estimate of the population mean for those who used the automated electric snow thrower.

111 < < 137

102 < < 142

122 < < 152

109 < < 143