How do smartphone owners use their smartphones when shopping in a grocery store? A sample of 731 smartphone owners in the United States revealed that 358 use their smartphone to access digital coupons, 355 look up recipes, 234 read reviews of products and brands, and 154 locate in-store items. a. For each smartphone user grocery shoppers construct a 95% confidence interval estimate for the population proportion. b. What conclusions can you reach concerning how smartphone owners use their smartphone. When shopping in a grocery store?