Gail needs to earn a c in her geology class. her current test scores are 76, 72, 65, and 73. her final exam is worth 3 test scores. in order to earn a c gail's average must lie between 70 and 79 inclusive. what range of scores can gail receive on the final exam to earn a c in the course?

Final test score should lie within the range of 21.33 and 36.33

Step-by-step explanation:

Given:

Test scores 76, 72, 65, and 73

Worth of final test score = 3

let the final test score be 'x'

thus,

Final test score = 3x

Now,

The average must lie between 70 and  79

i.e the minimum limit of average is 70 and maximum limit of average is 79

Also,

Average =

or

Average =

thus,

70 ≤    ≤ 79

or

70 × 5  ≤    ≤ 79 × 5

350  ≤    ≤ 395

or

350 - 286 ≤    ≤ 395 - 286

or

64  ≤    ≤ 109

or

21.33 ≤ x ≤ 36.33

Hence,

the final test score should lie within the range of 21.33 and 36.33