Suppose thatn=18data points were used to construct the given regression equation and that the standard error for the coefficient ofx₄is0.833. Construct a 90% confidence interval for the coefficient ofx₄. (Round your answers to two decimal places.)

lower limit

upper limit

Using the information of part (e) and level of significance10%, test the claim that the coefficient ofx₄is different from zero. (Round your answers to two decimal places.)

t=

tcritical=