Question: An ABCNews.com poll conducted by TNS Inter search June 13-17, 2001, posed the following question to a random sample of n 5 1024 adult Americans: "Scientists can change the genes in some food crops and farm animals to make them grow faster or bigger and be more resistant to bugs, weeds and disease. Do you think this genetically modified food, also known as bio-engineered food, is or is not safe to eat?" (http://www.pollingreport.com/food.htm, September 17, 2002). The percentages that selected each response were as follows: Is safe (35%), Is not safe (52%), and No opinion (13%).
a. What is the approximate margin of error for this survey?
b. Find approximate 95% confidence intervals for the proportion and the percentage of adult Americans who would have said in June 2001 that they think genetically modified food is not safe.
c. Note that a majority of the sample (52%) thought that genetically modified food is not safe. Based on the confidence interval you found in part (b), can you also conclude that a majority of the population at that time thought that genetically modified food was not safe? Explain.