TeX source:

r_{w g(J)} \frac{J\left[1- \overline{s_{x_{j}}^{2}} / \sigma_{E}^{2}\right]}{J\left[1- \overline {s_{x_{j}}^{2}} / \sigma_{E}^{2}\right]+\left(\overline{s_{x_{j}}^{2}} / \sigma_{E}^{2}\right)}