Find the required probability for usual distribution.
1. The marks on the verbal portion of the SAT have a normal distribution with a mean of 500 and standard deviation of 100.
-Explain what is the proportion of people that score at least 700?
-If a student who took the SAT is arbitrarily chosen what is the probability that the student scores at most 350 on the verbal portion?
-George keep score higher than about 62% of the people on the verbal portion of the SAT. Explain what is George's score?
2. The usual number of hours of sleep per night that a college freshman gets is 6.5 with a standard deviation of 1.8 hours. If 35 college freshmen are arbitrarily chosen find the probability that they average at least seven hours of sleep per night.