Bob and Doug are both 100-meter sprinters. Bob's sprint time is normally distributed with a mean of 10.00 seconds and Doug's spr
int time is also normally distributed, but with a mean of 9.90 seconds. Both have the same standard deviation in sprint time σ. Assuming that Bob and Doug have independent sprint times, and given that there is a .95 chance that Doug beats Bob in any given race, find σ.