The Mean Weight of Trucks Traveling on a Particular Section

The mean weight of trucks traveling on a particular section of I-475 is not known. A provincial
Highway inspector needs an estimate of the mean. He selects a random sample of 49 trucks
Passing the weighing station and finds the mean is 15.8 tonnes, with a standard deviation of the
Sample of 4.2 tonnes. What is probability that a truck will weigh less than 14.3 tonnes?

A) 0.0062
B) 0.3632
C) 0.1368
D) 0.4938