Answer:
Tom must score 95 on his last test to have an average of 92.
Explanation:
Tom's average score (92) = the sum of all his five grades/the number of grades (5)
Given that A is the grade Tom must receive on his last test, we have the equation as follows:
92 = (89+94+86+96+A)/5
<=> A = 92 × 5 - (89+94+86+96)
=> A = 95