Step 1 :Convert the time taken to hours: 1 hour and 30 minutes = 1 + \(\frac{30}{60}\) = 1.5 hours
Step 2 :Calculate the average speed: \(\frac{36 \text{ miles}}{1.5 \text{ hours}} = 24 \text{ mph}\)
Step 3 :\(\boxed{24.0}\) is the average speed of the bus in mph