Use Sheet 1 of the Excel file to answer the following questions. A school administrator believes that the mean class GPAs for a given course are higher than the preferred mean of 2.75 at a significance level of 0.05, and checks a randomly chosen sample of 50 classes. Create a histogram, and calculate x¯, the t-statistic, and the p-value. From the histogram, can normality be assumed? x¯= t= p= Since the p-value is evidence exists that the mean GPA is greater than 2.75. than the significance