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DATABRICKS-CERTIFIED-PROFESSIONAL-DATA-SCIENTIST · Question #49

DATABRICKS-CERTIFIED-PROFESSIONAL-DATA-SCIENTIST Question #49: Real Exam Question with Answer & Explanation

The correct answer is D. Option D. This is the standard solution of the normal equations for linear regression. Because A is not square, you cannot simply take its inverse.

Question

Assume some output variable "y" is a linear combination of some independent input variables "A" plus some independent noise "e". The way the independent variables are combined is defined by a parameter vector B y=AB+e where X is an m x n matrix. B is a vector of n unknowns, and b is a vector of m values. Assuming that m is not equal to n and the columns of X are linearly independent, which expression correctly solves for B?

Options

  • AOption A
  • BOption B
  • COption C
  • DOption D

Explanation

This is the standard solution of the normal equations for linear regression. Because A is not square, you cannot simply take its inverse.

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