The makers of a soft drink want to identify the average age of its consumers. a sample of 16 consumers is taken. the average age in the sample was 22.5 years with a standard deviation of 5 years. a) construct a 95% confidence interval for the true average age of the consumers. b) construct an 80% confidence interval for the true average age of the consumers. c) discuss why the 95% and 80% confidence intervals are different.