It has been projected that the average and standard deviation of the amount of time spent online using the Internet are, respectively, 14 and 17 hours per person per year (many do not use the Internet at all!).

a What value is exactly 1 standard deviation below the mean?

b If the amount of time spent online using the Internet is approximately normally distributed, what proportion of the users spend an amount of time online that is less than the value you found in part (a)?

c Is the amount of time spent online using the Internet approximately normally distributed? Why?