A factory that manufactures bolts is performing a quality control experiment. Each object should have a length of 18 centimeters. The factory believes that the length of the bolts exceeds this value and measures the length of 80 bolts. The sample mean bolt length was 18.04 centimeters. The population standard deviation is known to be =0.25 centimeters.

What is the test statistic z?

What is the p-value?

Does suficient evidence exist that the length of bolts is actually greater than the mean value at a significance level of a=0.01?