Mean, Standard Deviation, and Normal Distribution

If the meanexam score in a class of 30 students is an 80 out of 100 and the standard deviationon the exam is 15, what percentage of students earned between 65 and 95, assuming a normal distributionof grades on the exam? How alarmed should a student with a score of 49 be with his grade?

This solution deals with questions related to the normal distribution, mean, and standard deviation of a problem.