Answer:
Strong Positive Linear Line Correlation
Step-by-step explanation:
According to the diagram, there is a strong positive linear line correlation between velocity and distance of galaxies. Hubble showed that galaxies are receding away from people with a velocity that is proportional to their distance from people more distant galaxies recede faster than nearby galaxies.
About the diagram: Velocity is the distance relation among extra-galactic nebulae. Radial velocities is corrected for solar motion, are plotted against distances estimated from involved stars and mean luminosities of nebulae in a cluster. The black discs and full line represent the solution for solar motion by using the nebulae individually; the circles and broken line represent the solution combining the nebulae into groups; the cross represents the mean velocity corresponding to the mean distance of 22 nebulae whose distances could not be estimated individually.