If Peter received grades of 88,83,75,and 80 on four tests in English, what is the minimum grade he has to score on the fifth test to have an average of at least 85 for the course?
85=(88+83+75+80+x)/5
85(5)=88+83+75+80+x
425-326=x
99=x
To find out the minimum grade Peter needs to score on the fifth test, we can use the concept of averages. The average of a set of numbers is calculated by adding up all the numbers and then dividing the sum by the total number of values.
In this case, Peter has taken four tests and received grades of 88, 83, 75, and 80. To calculate his current average, we need to add up these four grades and divide by 4 (since there are four grades).
\[(88 + 83 + 75 + 80) / 4 = 82.5\]
So, Peter's average for the first four tests is 82.5.
Now, we need to find out what Peter's average needs to be in order to have at least an average of 85 for the course. Since there will be a total of 5 grades, Peter's total score should be equal to or greater than 85 multiplied by 5.
\[85 * 5 = 425\]
Since Peter has already scored a total of 82.5 * 4 = 330 on the first four tests, he needs to score at least 425 - 330 = 95 on the fifth test to reach an average of 85 for the course.
Therefore, Peter needs to score a minimum of 95 on the fifth test to have an average of at least 85 for the course.