According to the University of Nevada Center for Logistics Management, 6% of all merchandise sold in the United States gets returned. A Houston department store sampled 80 items sold in January and found that 7 of the items were returned. Required:
a. Construct a point estimate of the proportion of items returned for the population of sales transactions at the Houston store.
b. Construct a 90% confidence interval for the proportion of returns at the Houston store.
c. Is the proportion of returns at the Houston store significantly different from the returns for the nation as a whole?