test is made of Ho: u=18 versus H,: #18. A sample of size n=47 is drawn, and x=20. The population standard deviation is o=6. (a) Compute the value of the test statistic z. (b) Is H, rejected at the a=0.05 level? (c) Is H, rejected at the =0.01 level? Part 1 of 3 (a) Compute the value of the test statistic. Round the answer to at least two decimal places. z = 2.29 Part: 1 / 3 Part 2 of 3 Choose the correct type of hypothesis test. Then find the critical values for a=0.05 and a=0.01. Round your answers to three decimal places, if necessary. Critical Values for a=0.05 Critical Values for a=0.01 Left-tailed O Right-tailed O Two-tailed and and