Two different formulas of an oxygenated motor fuel are being tested to study their road octane numbers. the variance of road octane number for formula 1 is o 1.5, and for formula 2 it is 05= 1.2. two random samples of size n1 = 15 and2= 20 are tested, and the mean octane numbers observed are x1 = 88.9 fluid ounces and x2=92.5 fluid ounces. assume normality. what sample size would be required in each population if you wanted to be 95% confident that the error in estimating the difference in mean road octane number is less than 1?