Jeffrey as an eight year old established and averagetime of 16.43 seconds for swimming the 25 yard freestyle with a standard deviation of point eight seconds his dad freaks out that jeffrey could swim the 25 yard freestyle faster by using goggles frank by jeffrey a new pair of expensive goggles in time jeffrey for the 1525 yard freestyle swim for the 15th swims fit jeffries average time with 16 seconds frank fact that the goggles jeffrey just went faster than the 16.4 three seconds conduct a hypothesis test using a preset of .05 assume that the swim time for the 25 yard freestyle our normal constructed 95% confidence interval for the mean