To calculate any speed, the equation is speed=distance/time Basically, you first need to take your 9 hours and 15 minutes and combine them into a number with a decimal value. So, 15*4=60 Sound familiar? Good, because 25*4=100, so they are the same here. So, we can say 9 hours and 15 minutes is equal to 9.25 Take this now: Speed=538/9.25 You get 58.1621, which you can round to 58.2 This is, of course, your final answer, so Joe drove at 58.16 mph
