Question 1074660
assume normality and random sample; also assume sd is unbiased estimator of true sd
test statistic is (xbar-mean)/(s/sqrt(n)) with critical value for t(0.975 df=19) of 2.093,  absolute value.
(46.6-50)/(5/sqrt(20)=-3.4*sqrt(20)/5=-3.041
This absolute value of this is greater than the critical value, so one would reject Ho and the claim at the 5% level.