The the mean of certain production process is known to be a pretty with a standard deviation of 2.5 the production manager Mein welcome any changes is the mean value of towards the higher side but would be like to safeguard Against The decrease the value of mid heel takes a sample of 12 item that give a mean value A 48.5 what is free and service should be the manager take for a production process is basis of sample result the value of 5% to significant for the one tailed test is a 1.645