The recommended adequate intake (RAI) of calcium for adults is 1000 mg. per day. To investigate the calcium intake of people living below the poverty level, a researcher obtained a random sample of 18 adults below the poverty level and found a mean daily calcium intake of 947.4 mg. Required:
a. Determine the margin of error
b. Find 95% confidence interval fo rthe population mean
c. Interpret the confidence inteval. ( explain what it tells us about the estimated mean daily camlium intake for the population).