The National Assessment of Educational Progress (NAEP) is a nationwide assessment of students’ proficiency in nine subjects: mathematics, reading, writing, science, the arts, civics, economics, geography, and U.S. history. The main NAEP assessments are conducted annually on samples of students from grades 4, 8, and 12.
In 2002, the reading scores for female students had a mean of 269 with a standard deviation of 33. Assume that these scores are normally distributed with the given mean and standard deviation.
Identify the scores that are three standard deviationsabove and below the mean of the population. For this example, the limits will be 269 ± (33)(3). The lower limit is . The upper limit is . The probability that a female student will have a score between these limits is .
A score of 302 is above the mean. As a result, the percentage of female students with scores below 302 is .
You can infer that 97.72% of the female students have scores above .
