Question 36 (2 points) A random sample of size 21 was taken from a normal population. The sample average was 9.87 and the sample SD was 1.17. At the significance level of 10%, what test should you use for testing whether the population mean equals 9.7? One sample z-test for the population mean. O two sample z-test for the population means. One sample z-test for proportions. two sample z-test for proportions. Oone sample t-test for the population mean. Question 37 (2 points) What is a critical value for a left-tailed z-test with a significance level of 5%? O-2.447 1.65 O-1.65 O-2.33 1.28