According to a research center, 21% of all merchandise sold in a particular country gets returned. A department store in a certain city sampled 80 items sold in January and found that 28 of the items were returned. (a) Construct a point estimate of the proportion of items returned for the population of sales transactions at the store in the given city. (b) Construct a 95% confidence interval for the proportion of returns at the store in the given city. (Round your answers to four decimal places.) am to (c) Is the proportion of returns at the store in the given city significantly different from the returns for the country as a whole? Provide statistical support for your answer. Develop appropriate hypotheses such that rejection of Ho will support the conclusion that the proportion of returns at the store in the given city is significantly different from the returns for the country as a whole. I mor O Ho: P = 0.21 H: P = 0.21 OHO: P ≤ 0.21 HP> 0.21 O Ho: P2 0.21 H:P < 0.21 O Ho: P >0.21 H: Ps 0.21 O Ho: P < 0.21 H: P≥ 0.21 Find the value of the test statistic. (Round your answer to two decimal places.) Activate Windows Go to Settings to activate Windows.