Coyotes are nocturnal, but it is not uncommon to see them out during the day. Unless it was displaying obvious signs of being sick (major hair loss, trouble moving, very lethargic, etc), simply seeing it during the day is not an indication that the coyote is sick.
The fact that the coyote moved away when you yelled at it is a good sign. It is when coyotes get overly comfortable in an area and people make food readily available (pet food left outside, trash accessible, grills not kept clean) that conflicts between coyotes and people can occur. Make sure that the neighbors know that a coyote is around. Children should be taught that if they see a coyote they should yell for an adult, don't turn and run (that is prey behavior and would encourage the coyote to come in closer), instead they should face the coyote and put their arms up in the air and wave them around (this makes them look bigger), and yell at the coyote. Pets should not be left outside at night.
There are lots of coyotes, and most do not cause a problem. They mainly feed on mice, voles, and rabbits. So you probably will not need to do anything. But if the coyote starts to go after pets then a nuisance wildlife control operator may need to be hired to trap it. If you have more questions please feel free to e-mail me again.
