6.8 Suppose that a study was conducted to predict whether an individual regularly smoked, or the expected probability of smoking, based on four continuous predictors such as x1

= smoking exposure, x2

= healthy lifestyle (e.g., diet, exercise), x3

= annual income, and x4

= years of schooling. Further, suppose that the value of −2ln(likelihood) for the model containing all four predictors is 558.

a. If the value of −2ln(likelihood) for the model containing none of the predictors is