The Number of Hours Per Week That High School Students $\overline{ y}$

Multiple Choice

The number of hours per week that high school students spend on homework is normally distributed,with a mean of 12 hours and a standard deviation of 3 hours.50 students are chosen at random.Let $\overline{ y}$ represent the mean number of hours spent on homework for this group.Find the probability that $\overline{ y}$ is between 10.8 and 13.0.

A) 0.0078
B) 0.286
C) 0.9886
D) 0.4711
E) 0.0143