A technology company decided to change the amount spent on marketing on the two social media sites, LinkedIn and YouTube, to determine the effect on their click$-$through rate. Their original strategy was to split the budget $50/50$

and market to both media sites equally. They switched their strategy to only spend $35\%$

of their marketing budget on LinkedIn and $65\%$

on YouTube. After switching to the new strategy and collecting data for two months, they found that the click$-$through rate increased with the new marketing strategy.

Step $3$ of $3$ : Identify the control group and the experimental group.