The multiple linear regression model y = 0 + 1x1 + 2x2 is fitted to a data

The multiple linear regression model
y = β0 + β1x1 + β2x2
is fitted to a data set with n = 20 observations, and the parameter estimates β^0 = 104.9, P\ = 12.76, and β^1 = 409.6 are obtained.
(a) What is the fitted value of the expected value of the response variable when x1 = 10 and x2 = 0.3?
(b) If this fitted value has a standard error of 17.6, construct a two-sided 95% confidence interval for the expected value of the response variable at this point.