The National Assessment of Educational Progress (NAEP) conducts 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 2000, the science scores for female students had a mean of 146 with a standard deviation of 35. Assume that these scores are normally distributed with the given mean and standard deviation.
Which of the following are properties of the normal curve representing the distribution of the scores? Check all that apply.

a. The two ends of the curve approach the horizontal axis but never touch it.
b. The curve is symmetrical about a vertical line through 332.
c. One-half of the total area under the curve is below 264.
d. The curve is symmetrical about a vertical line through 264.
e. One-tenth of the total area under the curve is below 264.
f. One-half of the total area under the curve is above 264.