Whitney is an economics major and predicts that the cost spent on text books for her major is significantly more tham last year. a random sample of 14 economics majors were surveyed for a hypothesis test about the mean amount spent on textbooks this year. she conducted a one-mean hypothesis test at the 1% significance level, to test her prediction that the cost spent on text books is more than last year's at 450 dollars. df to.05 to.10 to.025 to.01 to.005 13 1.350 2.160 2.650 3.012 1.771 14 1.345 1.761 2.145 2.624 2.997 1.341 1.753 2.131 2.602 2.947 15 2.921 16 1.337 1.746 2.120 2.583 determine the critical value(s) using the partial t-table above. if entering two critical values, use .