The use of topical painkiller ointment or gel rather than pills for pain relief was approved just within the last few years in the US for prescription use only. Insurance records show that the average copayment for a month’s supply of topical painkiller ointment for regular users is $30. A sample of n = 75 regular users found a sample mean copayment of $27.90.
(a) Identify each of 30 and 27.90 as a parameter or a statistic and give the appropriate notation for each.
(b) If we take 1000 samples of size n = 75 from the population of all copayments for a month’s supply of topical painkiller ointment for regular users and plot the sample means on a dotplot, describe the shape you would expect to see in the plot and where it would be centered.
(c) How many dots will be on the dotplot you described in part (b)? What will each dot represent?