Find the appropriate rejection regions for the large-sample test statistic z in these cases. (a) A left-tailed test at the 1% significance level. (Round your answers to two decimal places. If the test is one-tailed, enter NONE for the unused region.) z > z < (b) A two-tailed test with α = 0.01. (Round your answers to two decimal places. If the test is one-tailed, enter NONE for the unused region.) z > z < (c) Suppose that the observed value of the test statistic was z = −2.39. For the rejection regions constructed in parts (a) and (b), which one is the appropriate conclusion for the tests. (Enter A, B, C, or D.) A. We do not reject the null hypothesis for part (a). The null hypothesis will be rejected at the 1% level in part (b). B. The null hypothesis will be rejected at the 1% level in part (a). We do not reject the null hypothesis for part (b). C. We do not reject the null hypothesis for part (a) or part (b). D. The null hypothesis will be rejected at the 1% level in both part (a) and part (b).

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Solution =>(9) To find the critical value for left-tailed test.:." critical value "=-z_(alpha)alpha=" level of significance "=1%=0.01To find z_(x)=z_(0.01)1-x=1-0.01(1-x)=0.99see in the z-table in for what xalues of z. the area is nearly equal to 0-99. 50 for z=2.33 the area is 0.9901 which is nearly equal to 0.99 .:." critical value "=-2.33." (From "z"-table) ":." iritical region "=z < -2.33If the test is left-itailed or right tailed then it is one-teiled test.:. so cobove test is - left-teiled test which is one-tailed test. so trat unused regionb) To find the critical value for two-teiled test.{:[:." critical value "=-z_(xx12)" and "z_(alpha12)],[alpha=" level of significance "=1%=0.01],[(alpha12)=0.005],[1-(alpha12)=1-0.005],[=0.995]:}see in the z-table for what xalue of z, the avea is nearly eayal to 0.995 . z=2.58 ... See the full answer