A tech company is developing two different versions of a mobile app interface $($SimpleDesign and AdvancedDesign$)$ and wants to assess user satisfaction. In a usability test, $50$ participants were randomly assigned to interact with either SimpleDesign or AdvancedDesign. User satisfaction scores were collected, showing that participants using SimpleDesign had a mean satisfaction score of M $=8($s $=1\mathrm{.}5),$ while those using AdvancedDesign had a mean score of M $=9($s $=1).$ Calculate the pooled variance.