A sample of 40 speedometers for 'pragia' is obtained in tamale and each is calibrated to check for accuracy at 55kmh. the resulting sample average and sample standard deviation 53.8and 13...

A sample of 40 speedometers for 'pragia' is obtained in tamale and each is calibrated to check for accuracy at 55kmh. the resulting sample average and sample standard deviation 53.8and 13 respectively. does the sample information suggest that the true mean for the speedometer is not accurate at 55kmh. use an alpha level of 0.01