Astudent has scores of 74%, 78% and 70% on three exams. what score is needed on a fourth exam for the student to earn an average of 80% ?

(74 + 78 + 70 + x) / 4 = 80

Divide each number by 4.

18.5 + 19.5 + 17.5 + x = 80

Add the numbers you know so far.

18.5 + 19.5 + 17.5 = 55.5

You need 24.5.

Now, since we divided all the others by 4, we have to multiply 24.5 by 4 to see what the exam score would be.

24.5 * 4 = 98.

To get an average of 80%, the student would need to get a 98 on their fourth exam.

well there are two answers for that.

1: you need 120 ones then that will equal up to 120.

2: you could also do one 100 and 2 tens.

those are the answers that i have thought of.

30 feet

step-by-step explanation:

that would be 2 1/2 * 12

= 24 + 6

= 30 feet   (answer)