Modern astronomical observatories often consist of a large number of parabolic reflectors, connected by computers, used to analyze radio waves. Each dish focuses the incoming parallel beams of radio waves to a precise focal point, where they can be synchronized by computer. If the surface of one of the parabolic reflectors is described by the equation $$\frac{x^2}{100}+\frac{y^2}{100}=\frac{z}{4},$$ where is the focal point of the reflector? (See [link].)