You also need to take the TBAS as a 300 prior to going up for the rated board. The TBAS is another exam and part of another portion of the scoring known as PCSM. This is also where having flight hours play a factor.
I would also state that it is true ERAU does produce the most rated slots after USAFA, BUT do not confuse numbers with statistics. Statistically, ERAU is not any different than most units. I.E. the year that my DS commissioned, his detachment (awarded #1 large detachment in AFROTC) had 100% selection rate, the national average was 93% and ERAU that year had 91%. However, because ERAU, also considered a large det. had more cadets, by sheer numbers they had the most rated.
My suggestion is to major in something you enjoy. You are going to need that gpa to get to SFT. No SFT = no commission.
I would also say is do not try to game the system with your major for scholarships.
1. There have been years where some Aero majors did not get a scholarship. Why? Because HQ AFROTC does not want 100% of their cadets as Aero majors, they need various majors, such as Computers, Mechanical Engineers, Electrical, etc. Thus, they will take that ME major over the Aero because they might need more MEs.
2. There have been years where they say they are critically manned regarding a specific major. In this case they placed a limit on how many they would award a rated slot. I recall for a couple of years it was that way for EEs. I will not swear, but I think it was @25% that they allowed to go rated. See above what JustABill stated regarding other factors. IOWS, you could have a 3.3 cgpa, but in that yr group if the top 25% had a 3.6, and higher AFOQT/PCSM scores, than you went EE.
Finally, when you apply for the scholarship as a tech major you do have a higher chance of getting the scholarship. @85% go to tech majors. However, it is not uncommon for kids after a semester to say I hate this major and now want to go to let's say Econ (non-tech). The problem is that HQ AFROTC will have to approve you going from tech to non-tech, and the reality is 99% of the time they will not approve the change. You can change it, but it will mean the loss of your scholarship. This can be a problem if you need the scholarship to attend the school. IOWS, do you stay with a major that you are academically struggling with, risking SFT and UPT or do you go in debt and go non-tech, which is still a risk for SFT selection.