To get a B in American Government, you must have an average of at least 80% on four exams. The first three exams are 100 points each, and the final is 200 points. If you have scored 75, 87, and 83 on the first three exams, what must you score on the final

To get a B in American Government, you must have an average of at least 80% on four exams.

The first three exams are 100 points each, and the final is 200 points. If you have scored 75, 87,

and 83 on the first three exams, what must you score on the final to earn a B in the course?

Solve the problem algebraically and show all of your support work.

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Fall 2003 – O’Brien

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Quadratic Applications Solve the following problems algebraically. Do not use a graphing calculator.

27. A textile manufacturer has daily production costs of C=.55×2−110x+10,000 where C is the

total cost (in dollars) and x is the number of units produced. Determine how many units should be

produced each day to yield a minimum cost. What is that minimum cost? Show all of your work.

28. The Guinness Book of World Records reports that German shepherds can make vertical leaps

over 10 feet when scaling walls. If the distance d (in feet) off the ground after t seconds is given

by the equation d=−16t2+24t+1, for how many seconds is the dog more than 9 feet off the

ground? Show all of your work or explain how you came up with your solution.