Joey's first 14 quiz grades in a marking period were as follows: 86 84 91 75 78 80 74
87 76 96 82 90 98 93
Suppose Joey has an unexcused absence for the 15th quiz, and he receives a score of 0.
What is the range of Joey's first 14 quiz grades? What is the range of Joey's quiz grades after his unexcused absence?

1.  

2.  

Step-by-step explanation:

Given

The data of quizzes

Required

Solving (a): Range of the 14 quizzes

In this case;

So;

Solving for (b): Range of 15 quizzes

In this case;

Least = 0

So; Range becomes

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,

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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