Question

londell has scored 75, 74, and 80 on his previous three tests. what score does londell need on the next test to have an average (mean) is 77? answer: question help: read written example check answer

Explanation:

Step1: Recall the mean formula

The mean (average) of a set of numbers is given by the sum of the numbers divided by the count of the numbers. Let the score on the next test be \( x \). The total number of tests after the next one will be \( 4 \) (since there are 3 previous tests and 1 new test). The mean is \( 77 \), so we can set up the equation: \(\frac{75 + 74 + 80 + x}{4}=77\)

Step2: Simplify the numerator

First, calculate the sum of the previous three scores: \( 75+74 + 80=229\). So the equation becomes \(\frac{229 + x}{4}=77\)

Step3: Solve for \( x \)

Multiply both sides of the equation by \( 4 \) to get rid of the denominator: \( 229+x=77\times4\). Calculate \( 77\times4 = 308\). Then, subtract \( 229 \) from both sides: \( x=308 - 229\)

Step4: Calculate the value of \( x \)

\( 308-229 = 79\)

Answer:

\( 79 \)