Answer:
Step-by-step explanation:
If f represents the score on the final exam, the final grade (g) is ...
g = 83%×0.70 + f×0.30
g = 58.1% + 0.30f
A. If f is 100%, then the resulting final grade is
g = 58.1% + 0.30×100% = 88.1%
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B. To earn 75%, the grade on the final would need to be ...
75% = 58.1% + 0.30f
16.9% = 0.30f
16.9%/0.30 = f ≈ 56.3%