A random sample of 81 eighth grade students scores on a national mathematics assessment test has a mean score of 279 This test result prompts a state school administrator to declare that the mean score for the state s eighth graders on this exam is more than 270 Assume that the population standard deviation is 39 At 0 05 is there enough evidence to support the administrator s claim Complete parts a through e a Write the claim mathematically and identify Ho and H Choose the correct answer below OA Ho 2270 claim H 270 O D Ho 270 claim Ha 270 b Find the standardized test statistic z Z Round to two decimal places as needed B Ho 270 Ha 270 claim E Ho 270 Ha 270 claim CLOS C Ho 270 Ha 270 claim OF Ho 270 claim Ha 270