There is an assumption that nothing in the error term should correlate with the explanatory variable (x) of interest and outcome variable of (y). It does not allow any linear relation between two or more variables. If there is a relation between the variable it the the violation of this assumption.
Michelle: x Ian: 5x Joe: 7x Michelle + Ian + Joe = 208 berries x + 5x + 7x = 208 Combine like terms: 13x = 208 Divide both sides by 13: x = 16 Joe = 7x = 7*16=112 Joe picked 112 berries
