Sandra has taken 3 Test this Quarter. She has scored an 78%, 76%, and a 93%. Sandra wants to earn at least and 85% for the Quarter. What score will she need to earn on her Final Test in order for her to Average at least an 85% for the Quarter? Then Explain what your answer means.

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step-by-step explanation:

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

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hope this