a) Standard deviation of 10 mean the fluctuation for values range from +10 to -10 from the mean.
b) Since the sixth student is 50 minutes, which is higher than the mean of 45 minutes, this will bring the over all mean higher that 45 minutes. Also, since 50 falls within the standard deviation range (35 to 55), this mean the new standard deviation will be smaller than 10.
