Bay Path University, in western Massachusetts, has agreed to acquire Boston-based Cambridge College, the two institutions announced Tuesday. The two private nonprofit institutions share a focus on career education, and they are comparably sized: Bay Path enrolls about 2,500 students, split between women-only undergraduate programs and coeducational graduate programs, while Cambridge offers programs in Boston and in Puerto Rico that serve more than 2,000 mostly adult learners. Officials said the acquisition has been in the works since last summer.