Test whether the mean speed is 55 mph before and 60 mph after at the α=5% significance level. Explain each step and interpret the results.
Suppose our goal is to quantify the impact of the repeal of the national maximum speed limit on average speeds on U.S. roads. Representative speed data are collected for particular time periods before and after the repeal. The spreadsheet “hw1_speed_data.csv” contains vehicular speed data before and after the repeal of a speed limit law. Use […]