Jeffrey as an eight year old established a mean time of 16 43 seconds for swimming the 25 yard freestyle with a standard deviation of 0 8 seconds His dad Frank thought that Jeffrey could swim the 25 yard freestyle faster using goggles Frank bought Jeffrey a new pair of expensive goggles and timed Jeffrey for 15 25 yard freestyle swims For the 15 swims Jeffrey s mean time was 16 seconds Frank thought that the goggles helped Jeffrey to swim faster than the 16 43 seconds Calculate the test statistic T S Use 2 decimal places