Leah’s average for the past three quizzes in history is 84. What must she make on the fourth quizzes to increase her average to 88?
To find out what Leah must make on the fourth quiz, we first need to determine the sum of her scores on the first three quizzes.
Her average score for the past three quizzes is 84, so the sum of her scores is 84 * 3 = <<84*3=252>>252.
To increase her average to 88, the sum of her scores on all four quizzes must be 88 * 4 = <<88*4=352>>352.
To determine what Leah must make on the fourth quiz, subtract the sum of her scores on the first three quizzes from the sum of scores needed for an 88 average: 352 - 252 = <<352-252=100>>100.
Therefore, Leah must make a score of 100 on the fourth quiz to increase her average to 88.
To solve this problem, we can use the concept of average.
Let's denote the score Leah needs to achieve on the fourth quiz by "x".
We know that Leah's average for the past three quizzes is 84, so the total score for those three quizzes is 3 * 84 = 252.
We also know that Leah wants to increase her average to 88, so the total score for all four quizzes should be 4 * 88 = 352.
To find out what Leah needs to score on the fourth quiz, we subtract the total score from the first three quizzes from the target total score for all four quizzes:
352 - 252 = 100
So, Leah must score 100 on the fourth quiz to increase her average to 88.
To determine what Leah must make on the fourth quiz, we need to understand the average formula.
The average is calculated by adding up all the values and then dividing the sum by the number of values.
In this case, let's assume Leah's score on the fourth quiz is "x."
Leah's average for the past three quizzes is 84, so the sum of her scores on those three quizzes is 84 * 3 = 252.
To increase her average to 88, we need to consider the total sum of all four quizzes. The equation becomes:
(252 + x) / 4 = 88.
To solve this equation for "x," we can follow these steps:
Step 1: Multiply both sides of the equation by 4 to eliminate the denominator:
252 + x = 88 * 4.
Step 2: Simplify the equation:
252 + x = 352.
Step 3: Subtract 252 from both sides of the equation to isolate "x":
x = 352 - 252.
Step 4: Simplify the equation:
x = 100.
Therefore, Leah must make a score of 100 on the fourth quiz to increase her average to 88.