Police recorded the average speed of cars driving on a busy street by a school. For a sample of 16 speeds, it was determined that the average amount over the speed limit for the 16 speeds was 11.4 mph with a standard deviation of 6 mph. The 90% confidence interval estimate for this sample is 8.77 mph to 14.03 mph. a) What is the margin of error for this problem? b) What size sample is needed to reduce the margin of error to no more than 1 17

Police recorded the average speed of cars driving on a busy street by a school. For a sample of 16 speeds, it was determined that the average amount over the speed limit for the 16 speeds was 11.4 mph with a standard deviation of 6 mph. The 90% confidence interval estimate for this sample is 8.77 mph to 14.03 mph. a) What is the margin of error for this problem? b) What size sample is needed to reduce the margin of error to no more than 1 17

ENGR.ECONOMIC ANALYSIS

14th Edition

ISBN:9780190931919

Author:NEWNAN

Publisher:NEWNAN

Chapter1: Making Economics Decisions

Section: Chapter Questions

Problem 1QTC

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