IV (04.5, 2.5). 3 Test scores. Many states assess the skills of their students in various grades. One program that is available for this purpose is the National Assessment of Educational Progress (NAEP). One of the tests provided by the NAEP assesses the reading skills of 12th-grade students. In a re- cent year, the national mean score was 288 and the standard deviation was 38. Assuming that these scores are approximately Normally distrib uted, N(288, 38), use the 68-95-99.7 rule to give a range of scores that includes 95% of these students. Use the 68-95-99.7 rule. Refer to the previous exercise. Use the 68-95- 99.7 rule to give a range of scores that includes 99.7% of these students. andardizing observations