How much money do people spend on graduation gifts? In 2007, the National Retail Federation (www.nrf.com) surveyed 2815 consumers who reported that they bought one or more graduation gifts that year. The sample was selected in a way designed to produce a sample representative of adult Americans who purchased graduation gifts in 2007. For this sample, the mean amount spent per gift was $55.05. Suppose that the sample standard deviation was $20. Construct and interpret a 98% confidence interval for the mean amount of money spent per graduation gift in 2007.
Answer to relevant QuestionsIn June 2009, Harris Interactive conducted its Great Schools Survey. In this survey, the sample consisted of 1086 adults who were parents of school-aged children. The sample was selected in a way that makes it reasonable to ...The article “Most Canadians Plan to Buy Treats, Many Will Buy Pumpkins, Decorations and/or Costumes” (Ipsos-Reid, October 24, 2005) summarized results from a survey of 1000 randomly selected Canadian residents. Each ...The formula described in this section for determining sample size corresponds to a confidence level of 95%. What would be the appropriate formula for determining sample size when the desired confidence level is 90%? 98%? In the article “Fluoridation Brushed Off by Utah” (Associated Press, August 24, 1998), it was reported that a small but vocal minority in Utah has been successful in keeping fluoride out of Utah water supplies despite ...Given below are the sodium contents (in mg) for seven brands of hot dogs rated as “very good” by Consumer Reports (www.consumerreports.org): a. Use the given data to produce a point estimate of m, the true mean sodium ...
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