In a recent study, 2006 randomly selected US adults (age 18 or older) were asked to give the number of people in the last six months ‘‘with whom you discussed matters that are important to you.” The average number of close confidants was 2.2, with a standard deviation of 1.4.
(a) Find the margin of error for this estimate if we want 99% confidence.
(b) Find and interpret a 99% confidence interval for average number of close confidants.