A dense spherical ore body has an excess mass of $\\Delta M = 3 \\times 10^9$ kg and is buried at depth $z = 100$ m. The vertical gravity anomaly directly above the sphere is $\\Delta g = \\frac{G \\Delta M}{z^2}$, where $G = 6.67 \\times 10^{-11}$ m$^3$/(kg\cdot s$^2$). What is the gravity anomaly $\\Delta g$ in microgals ($1 \\text{ }\\mu\\text{gal} = 10^{-8}$ m/s$^2$)?