Jim has grades of 84, 65, and 76 on three math tests. What grade must he obtain on the next test to have an average of exactly 80 for the four tests?
84+65+76 = 225
to have an 80 average of 4 tests he needs 320 total points.
good luck, Jim.
There will be four exams this semester. You've already taken the first three. Your scores were 60, 82, and 93. What score must you get on your fourth test in Oder to earn at least an 80% in the class
To find out the grade Jim must obtain on the next test, we need to understand how averages work. The average is calculated by adding up all the numbers and dividing by the total number of values.
In this case, Jim has taken three tests, and his grades are 84, 65, and 76. To calculate the average, we need to add these three grades together and divide by the total number of tests, which is 3.
(84 + 65 + 76) / 3 = x, where x represents the current average.
To calculate the next average, we need to include the grade Jim obtains on the fourth test. So, we add the grade on the fourth test and divide by the total number of tests, which is 4 this time.
(84 + 65 + 76 + y) / 4 = 80, where y represents the grade Jim needs to obtain on the fourth test.
To solve this equation for y, we need to multiply both sides by 4 to eliminate the fraction:
84 + 65 + 76 + y = 80 * 4
(84 + 65 + 76) + y = 320
225 + y = 320
Now, solve for y by subtracting 225 from both sides of the equation:
225 + y - 225 = 320 - 225
y = 95
Therefore, Jim must obtain a grade of 95 on the next test to have an average of exactly 80 for the four tests.