According to a recent Women in the Workplace study from Lean In and McKinsey, the most significant barrier women face in business these days isn’t the glass ceiling. Instead, it’s the floor—the barrier to entry-level management positions. Although women now own 4 out of every 10 businesses in the U.S. and are making great strides at the top of the career ladder, they’re still missing from entry-level and middle-management positions. That’s something companies of all sizes need to address. Women in business mean greater successIt’s not just about diversity (although that’s a worthy goal in itse…