A regression model Y = β 0 + β 1 x 1 + β 2 x 2 + β 3 x 3 + ?has been fit to a sample of n = 25 observations. The calculated t -ratios j = 1, 2, 3 are as follows: for β 1 , t 0 = 4.82, for β 2 , t 0 =...

A regression model
Y
= β₀+ β₁
x
₁+ β₂
x
₂+ β₃
x
₃+ ?has been fit to a sample of
n
= 25 observations. The calculated
t-ratios
 j = 1, 2, 3 are as follows: for β₁,
t
₀= 4.82, for β₂,
t
₀= 8.21 and for β₃,
t
₀= 0.98.

(a) Find
P-values for each of the
t-statistics.

(b) Using α = 0.05, what conclusions can you draw about the regressor
x
₃? Does it seem likely that this regressor contributes significantly to the model?