When an introductory statistics course has been taught live, the average final numerical grade has historically been 71.6% with a standard deviation of 8.8%. Twenty students were selected at random to take a new online version of the same course, and the average final numerical grade for these students was found to be 69.2%. Assuming that the individual grades are normally distributed and that the population standard deviation is still 8.8%, is there sufficient evidence to indicate that students taking the online version of the course score lower, on average, than students taking the traditional live version of the course? Use the p-value method to conduct an appropriate hypothesis test at the 5% level of significance. Comment on the validity of your conclusion.