A researcher wants to estimate the average grocery bill of households whose members shop at a particular supermarket to within $10, with 95% confidence. How big a sample size is necessary? A preliminary sample revealed a standard deviation of $32.45.
Answer to relevant QuestionsA student wants to estimate the average mark on a statistics test to within 5 marks (out of 100), with 95% confidence. A preliminary sample yielded a standard deviation of 15.54. How big a sample size is necessary? Return to the confidence interval you constructed for Develop Your Skills 8.2, Exercise 9.You believe that the average mark on the statistics test was 50%. Does the sample evidence support your belief? What level of ...A random sample of 400 Canadian grocery shoppers reveals that 26% of them are trying to make healthier food choices. a. Construct a 90% confidence interval estimate of the proportion of all Canadian grocery shoppers who are ...A car rental agency is trying to make staffing plans. The early morning is always a busy time for rentals. The agency keeps track of the number of customers who pick up rental cars in the 8 A.M. to 10 A.M. period for a ...How big a sample is necessary to estimate, to within 2 percentage points, the proportion of new graduates of a business program who are willing to relocate to find a job, with 90% confidence? If your college graduates only ...
Post your question