A sample of 49 observations is selected from a normal population. The sample mean is 21, and the population standard deviation is 4. Conduct the following test of hypothesis using the 0.05 significance level. : > 20 10 points a. Is this a one- or two-tailed test? 00:23:33 O "One-tailed"-the alternate hypothesis is greater than direction. O "Two-tailed"-the alternate hypothesis is different from direction. b. What is the decision rule? (Round your answer to 2 decimal places.) , whenzar .. Reject Do not reject c. What is the value of the test statistic? (Round your answer to 2 decimal places.) alue of the test statistic 1.75