Question: need help with the question,

John's company is involved in a lawsuit with a customer, Beth.John argues that for fifty years the higher courts in the state have decided cases involving circumstances similar to his case in a way that indicates he can expect a ruling in his company's favor.

1- is this s a valid argument, if it is why?

2- is the judge in this case must rule as those other judges decide and why?

It's better if the answer site sources (legal issues or doctrine) from the text ( business law today the essentials 12th edition) to back the response.