the average weight of a package of rolled oats is supposed to be at least 18 ounces. a sample of 18 packages shows a mean of 17.78 ounces with a standard deviation of 0.41 ounce. (a) at the 5 percent level of significance, is the true mean smaller than the specification? clearly state your hypotheses and decision rule. h0: μ ≥ 18. reject h0 if tcalc > −1.74 h1: μ < 18. reject h1 if tcalc < −1.74 h0: μ ≥ 18. reject h0 if tcalc < −1.74 h1: μ < 18. reject h1 if tcalc > −1.74