Answer:
[tex]6.25[/tex]
Step-by-step explanation:
[tex]We\ are\ given:\\Observations\ in\ the\ Set=(7,5,4,9)\\ As\ we\ know\ that,\\ Average\ or\ interchangeably\ mean=\frac{Total\ Sum\ of\ observations }{Total\ no.\ of\ observations} \\Here,\\Total\ sum\ of\ the\ observations=7+5+4+9=25\\Total\ number\ of\ observations=4\\Hence\ here,\\Mean/Average=\frac{25}{4}=6.25[/tex]