Jake is hoping that his mortgage firm will have one of the highest ratings in the country. He learns that the average score is 80 and his team's score is 86. He is initially disappointed as he had hoped for greater separation between the average and his company's score. He then learns that the standard deviation for the evaluation was 2.5. What is his company's z-score?

Can you show me the equation for the z-score using this word problem?