Oklahoma City, OK - According to Education Week's Quality Counts 2014 report, the United States education system received a C– on the K-12 Achievement Index, ranking Oklahoma number 10 on the list of states with the worst school systems.

For each state, Education Week evaluated the Chance for Success Index; K-12 Achievement; School Finance; Transitions and Alignment; Standards, Assessments and Accountability; and Teaching Profession. These six categories measure key education areas including test scores, graduation rates, standardized tests, teacher accountability and incentives, school spending, post-education employment, family demographics, and more.

Focusing in on specific areas of the report, Oklahoma received an overall score of 64.2; a high school graduation rate of 73.9%, which ranked 20th lowest nationally; per pupil expenditure of $9,075, which rated the state 8th lowest; and preschool enrollment at 43.5%, which placed Oklahoma 19th lowest in the U.S.

Oklahoma did receive an ‘A' in standards, assessments and accountability, but the overall score was affected by the ‘D' in student achievement.

Mississippi topped out at number one on the "worst" list with an ‘F' grade, while Massachusetts earned the number one spot on the "best" list with a ‘B' grade.