46. A researcher in the field of sports biomechanics believes he has found the \"ideal" running posture for sprinters. He selects a random sample of 12 high school track sprinters and records their best 200 m time [in seconds). Then he trains these sprinters over several days to run using his proposed \"ideal" posture. In the days after the training ends, these sprinters run several 200 m races, and the researcher records their best performance from this time period. The before-training and after-training times (in seconds) are given below. Use the sign test to test the claim that the proposed ideal running posture is effective (Le. the median of the \"before after" differences is positive). Use a 0.05 level of signicance. Sprinter Before After 1 22.1 22.3 2 23.4 22.8 3 25.7 24.9 4 20.6 20.6 5 26.4 26.1 6 28.9 26.7 7 24.9 25.2 8 24.3 24.5 9 25.1 24.7 10 25.8 25.4 11 23.1 23.4 12 22.7 22.2