Write the Word or Phrase That Best Completes Each Statement $y = f \left( \frac { 1 } { 3 } x \right)$

Short Answer

Write the word or phrase that best completes each statement or answers the question.
Provide the missing information.
-The graph of $y = f \left( \frac { 1 } { 3 } x \right)$ is the graph of $y = f ( x )$ with a (choose one: vertical stretch, vertical shrink, horizontal stretch, horizontal shrink).