As used in this chapter, the term "high school equivalency certificate" means a certificate issued jointly by the state board for community and technical colleges and the superintendent of public instruction which indicates that the holder thereof has attained standard scores at or above the minimum proficiency level prescribed by the state board for community and technical colleges on the high school equivalency test, which is a measure of high school equivalency in the areas of writing skills, social studies, science, reading skills, and mathematics.