A nutrition lab tested 40 hot dogs to see if their mean sodium content was less than the 325-mg upper limit set by regulations for “reduced sodium” franks. The mean sodium content for the sample was 322.0 mg with a standard deviation of 18 mg. Assume that the assumptions and conditions for the test are met.

a) Test the hypothesis that the mean sodium content meets the regulation.

b) Will a larger sample size ensure that the regulations are met?