IQs Suppose that IQs of East State Universitys students can be described by a Normal model with mean 130 and standard deviation 8 points. Also suppose that IQs of students from West State University can be described by a Normal model with mean 120 and standard deviation 10. a) We select a student at random from East State. Find the probability that this students IQ is at least 125 points. b) We select a student at random from each school. Find the probability that the East State students IQ is at least 5 points higher than the West State students IQ. c) We select 3 West State students at random. Find the probability that this groups average IQ is at least 125 points. d) We also select 3 East State students at random. Whats the probability that their average IQ is at least 5 points higher than the average for the 3 West Staters?
Chapter 5 --- Randomness and Probability Spin a penny example in class: What is the probability of a headWhy Why is it calledan empirical probability Are spins independent If the first 10 spins are heads is the 11 spin more likely or less likely to be a head What does the “Law of Averages” say How does the Law of LargeNumbersapply to spinning pennies Random Predictability If time permits we will draw some random samples using a Red Bead box. The box is filled with white, red and black beads. We will drawrandom samples of 50 beads from the box and count the number of colored (red or black) beads. Each sample is random and we can’t predict how many colored beads there will be in the next sample. However we can predict a pattern