Answer:
He needs at 79
Explanation:
He will be taking 6 quizzes.
Let x be the score on the final quiz
The average is found when we add up all the scores and divide by the number of scores
Average = (88+100+95+78+88+x) /6
The average is 88
88 = (88+100+95+78+88+x) /6
Multiply by 6 on each side
88*6 = (88+100+95+78+88+x) /6 *6
528 = (88+100+95+78+88+x)
Combine like terms
528 = 449+x
Subtract 449 from each side
528-429 = 449-449+x
79 =x
He needs at 79