A sample of 30 students kept track of the number of hours they watch television. Here are

the results: (10)

16, 11, 14, 13, 9, 9, 11, 13, 14, 12, 12, 24, 11, 14, 14,

15, 8, 17, 10, 11, 8, 7, 13, 17, 10, 19, 15, 13, 13, 8

a) Determine the mean and standard deviation of these data.

x=381 and x2=5225

(Answer to 2 decimal places if necessary)

b) Assume that the data is normally distributed, determine the probability that the number

of hours of television watched will be less than 10.

c) Assume that the data is normally distributed, determine the probability that the number

of hours of television watched will be more than 16.