jim has grades of 84, 65, 76 on three tests. what grade must he obtain on the next test to have an average of exactly 80% for all four tests?

84 + 65 + 76 = 225

0.8 * 400 = 320

320 - 225 = 95

(65 + 84 + 76 + x ) / 4 = 80

(Balance the Equation)

225 + x = 320 [65 + 84 + 76 + x = 320]

(Balance the Equation)

x = 320 - 225 = 95

y=5x-3 y=-3x+13

The sum of two consecutive numbers is 37. What are they

To find out what grade Jim must obtain on the next test to have an average of exactly 80% for all four tests, we can use the formula for average. The average is calculated by summing up all the grades and dividing by the number of tests.

Let's break it down step by step:

1. Calculate the sum of the three known grades:
84 + 65 + 76 = 225

2. Add the sum to the unknown grade and divide by the total number of tests:
(225 + X) / 4 = 80

3. Multiply both sides of the equation by 4 to remove the fraction:
225 + X = 320

4. Subtract 225 from both sides of the equation to isolate X:
X = 320 - 225

5. Calculate the result:
X = 95

So, Jim must obtain a grade of 95 on the next test to have an average of exactly 80% for all four tests.

( 84 + 65 + 76 + x ) / 4 = 80

84 + 65 + 76 + x = 4 * 80

225 + x = 320

x = 320 - 225 = 95