Question: The supplier of a particular brand of vitamin pills claims that the average potency of these pills after a certain exposure to heat and humidity is at least 65 and from the prior knowledge the potency of these pills is known to be normally distributed. Before buying these pills, a distributor wants to check if the supplier's claim is valid. To this end, the distributor will choose a random sample of 16 pills from a batch and measure their potency after the specified exposure. The results are: 63 72 64 69 59 65 66 64 65 73 69 60 71 68 65 62 Determine a 90% confidence interval for the true average potency of these pills after the specified exposure.