A. Do the following problems from Rosner, Fundamentals of Biostatistics, 5th Edition.
B. Consider the lead data from Assignment #1. Could you use low full-scale IQ as an indicator of hyperactivity? Plot the ROC curve. Pick a suitable cut-off point. (See Assignment #2 - Hints, Exercise #3 and Exercise #3 - Hints for hints.)
A. Do the following problems from Rosner, Fundamentals of Biostatistics, 5th Edition.
B. Consider the four plots of FFQ versus DR you did in Assignment #1 question B.3. Compute the correlation coefficient for each plot.
C. Suppose that the weight of suitcases being checked onto an airline flight can be described by a normal distribution with mean 25 kg and standard deviation 8 kg. The suitcases are randomly selected and loaded ten to a container. What is the probability that a container will weigh more than 300 kg? What is the probability that, out of five containers, at most two will weigh more than 300 kg?
D. Find the pdf, mean, variance and standard deviation for the score when a fair 6-sided die is rolled. Hence find the mean, variance and approximate pdf for the total score when 20 fair 6-sided dice are rolled independently.
E. Suppose that n = 9 observations X1, ..., X9 each have the same variance s2 but are autocorrelated, with
Corr(Xi, Xj) = rij = r|j - i|
for some 0 < r <1. Apply Equation 5.13 on page 138 to find the standard error of the sample mean. Show that the standard error increases from s /sqrt(n) to s as r increases from 0 to 1. What is the importance of this result for measurements replicated under laboratory conditions?