How to save time and money on education

I recently posted that we are throwing money at underperforming and poor students without getting much of a return. A reader left a comment, asking if I have suggestions for improvement. I do.

First, some facts: 
Three in ten jobs in the US do not even require a high school diploma.
Two out of three jobs do not require a college degree of any sort.
4 million students a year begin high school. 90% of them graduate.
70 percent of those who graduate from high school go on to enroll in college, despite the fact that only one third of jobs require a college degree.
Of course, of the 63 percent of high school students who attend college, less than half of them will actually graduate with a four year degree.
Of the students who get a college degree, twice as many get degrees in park, recreation, leisure, and fitness studies as there are students who receive degrees in mathematics or engineering.
Ten percent of college freshmen want to become a medical doctor. Less than 0.4% of them actually DO become doctors.

In other words, Americans are overeducated for the jobs that are there. We need to get away from the idea that every student needs to be ready for college, because even with all this money we are throwing at the issue, they just aren't learning. Here is my proposal:

At the end of the eighth grade, all students are given a proficiency exam. Students will be tested on proficiency in reading, vocabulary, and math skills. There will be no adjustment for special needs or learning disabilities.  Your score determines what taxpayer funded school you attend. If a student wishes to attend a higher level of school than the test determines that they are qualified for, then they can pay for the difference in cost out of their own pocket.

The lowest performing quintile will be sent to a school for the next two years to be taught how to be an adult: they will learn about  budgeting, along with basic life skills. At age 16, they will graduate and be able to get a job. This is all you need to mow lawns, work at a retail or fast food job, or any other job not requiring an employee to solve algebraic equations or write sonnets.

The second and third quintiles will attend a vocational high school. In this school they can learn general vocational skills like use of tools, construction, culinary, or mechanical skills. They can graduate at age 16 or 17 with the basic skills needed to work at the apprentice level of the skilled trades.

Fourth and fifth quintile students will be eligible for the college pathway. They graduate after taking classes on algebra, chemistry, composition, literature, and civics.

To be honest, we are doing this now. The school where I work pulls out the best performing students and puts them into "honors" classes or "AP" classes that are designed to prepare them for college. The remainder of the students are placed in fluff classes that are essentially babysitting to keep them out of their parents' hair until they are eighteen years old. All this would do is save us money by getting them off the gravy train earlier, and also give them life skills instead of paying lip service to the idea that every kid needs to be ready for college.