We don't know those hops are on Cox. We know the Hop 5 responding router to the ping request was Cox, but the next one COULD be Level 3 or some other back haul system.
Just because a ping isn't returned, doesn't mean it's a bad thing, OR a problem. Ping Requests have the lowest priority and routers can be configured to ignore them totally, OR, when the are busy, to ignore them. Remember your ping is measured in MS, Milliseconds, with is a Thousandth of a second.
BTW a search on the internet also returns this jewel - "Ping is measured in milliseconds, and the higher the number, the worse the lag time. Ping of about 100ms is considered average, and ping of 50ms or less is ideal for online gaming. Any number below 20ms is excellent.".
Hop #5 indicates your traffic is being passed off to the next peering partner for which shall not be named due to the ICMP de-prioritization. It's important to note that no actual loss is occurring here as if it were, you wouldn't be able to reach hops 10 and beyond. Can't prove it but I'm going to blame Zayo. If Iron Mountain Data Center's peering partner is Zayo I suspect things won't get better.