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Q54Section ST (Statistics (Q11–Q65))54 of 65

Properties of the ridge estimator

For Y∈RnY \in \mathbb{R}^{n}, X∈Rn×pX \in \mathbb{R}^{n \times p}, and β∈Rp\beta \in \mathbb{R}^{p}, consider a regression model Y=Xβ+ϵY = X \beta + \epsilon, where ϵ\epsilon has an nn-dimensional multivariate normal distribution with zero mean vector and identity covariance matrix. Let IpI_p denote the identity matrix of order pp. For λ>0\lambda > 0, let β^n=(XTX+λIp)−1XTY\hat{\beta}_n = (X^T X + \lambda I_p)^{-1} X^T Y, be an estimator of β\beta. Then which of the following options is/are correct?

Multiple select: one or more options are correct. Select all of them, then submit — marks need the exact set.

Options

Select every correct option, then submit.