. The makers of a soft drink want to identify the average age of its consumers. A sample of 25 consumers was taken. The average age in the sample was 33 years with a sample standard deviation of 4.5 years. Please answer the following questions:

a. Construct a 95% confidence interval estimate for the mean of the consumers' age.

b. Suppose a sample of 31 was selected (with the new mean age of 32 years and the same sample standard deviation). Construct a 95% confidence interval for the mean of the consumers' age.