1) his time would have to be less than 11.54
2)each member would have to run a time of about 11.91
3) Assuming that Dwane ran a time of 11.53 the average amount of time it took each member to run the 100 meters will be about 12.2 seconds per 100 meters
According to the empirical rule, roughly 68% of the scores fall between z = -1 and z = 1
You can use a calculator to get a more approximate answer. If you have a TI calculator, you can use the "normalcdf" function to type in normalcdf(-1,1)