SOLUTION: An arithmetic student needs an average of 70 or more to receive credit for the course. She scored 89, 73, and 76 on the first three exams. Write an inequality representing the scor

Algebra ->  Inequalities -> SOLUTION: An arithmetic student needs an average of 70 or more to receive credit for the course. She scored 89, 73, and 76 on the first three exams. Write an inequality representing the scor      Log On


   

Question 107779: An arithmetic student needs an average of 70 or more to receive credit for the course. She scored 89, 73, and 76 on the first three exams. Write an inequality representing the score she must get on the last test to receive credit for the course.
Answer by bucky(2189) About Me  (Show Source):
You can put this solution on YOUR website!
To have a 70 average on four tests she must score a total of 4 times 70 or 280 points.
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So far, on three tests she has collected a total of 89 + 73 + 76 = 238 points. Therefore,
to get a total of 280 points she must score 42 more points (280 - 238 = 42).
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On the fourth exam she must get at least 42 points to get credit for the course. She may get
more points than that, but she must get at least 42 points.
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Let S represent her score on the fourth (and last) test. You can write the answer in several ways:
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S+%3E+41
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This says her score on the last test must be greater than 41. Therefore, it must be at least
42.
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Or you could write:
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S+%3E=+42
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This means that her score can be equal to 42 or greater than 42.
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And if the maximum score on the test is 100, then you can establish the range of scores that
can get on the last test:
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41+%3C+S+%3C=+100
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Which says her score must be greater than 41, but less than or equal to 100.
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or you could write:
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42%3C=+S+%3C=+100
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which says her score must be greater than or equal to 42, but less than or equal to 100.
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Hope this helps you to understand the problem.
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