For which examines the relationship between LSD dosage and blood copper level:
a. Compute a 90% two-sided confidence interval on the slope.
b. Compute a 90% central confidence interval on the y intercept.
c. Compute a 90% confidence interval for the lowest mean copper level of those receiving a 50% dosage. d. Find the 90% prediction interval for the lowest copper level of an individual who would receive a 70% dosage.
e. Is it valid to use these intervals?