and interpret a ttest. John is the owner ofJohn's Jolly Small Aircraft Quick Oil Change. John is experimenting with a new oil change process and is trying to determine if the current process takes more time than the new process he is experimenting with. John is comparing sample mean times to evaluate his hypothesis about the population {total number of oil changes). Over the period of a week, he took a random sample of oil changes using both the old and new processes. Using the information John provided, you ran a ttest for independent samples. These are the results [a = .05}. tTest: TwoSample Assuming Unequal Variance Current Process New Process Mean 30.15 14.20 Variance 234.8?10526 14.16342105 Observations 20 20 Hypothesized Mean Difference 0 df 21 t Stat 4.520032841 PIT