John's average on all three tests, assuming a score of S on the third test, would be
(82 + 98 + S)/3
He wants the average to be at least 88, so solve the inequality:
(82 + 98 + S)/3 ≥ 88
82 + 98 + S ≥ 264
180 + S ≥ 264
S ≥ 84
So John needs to obtain a grade of at least 84 on the third test to get the average he wants.
The score on his third test is 84 so that his average is at least 88 given first two grades 82 and 98. This can be obtained by using the formula to find average.
Average of observations is the ratio of sum of observations to total number of observations.
Grade of first test=82
Grade of second test = 98
let grade of third test be x
Average of the grades = [tex]\frac{82+98+x}{3}[/tex] ≥ 88
[tex]\frac{180+x}{3}[/tex] ≥ 88 ⇒ x ≥ 246-180 ⇒ x ≥ 84
Hence we can say that the score on his third test is 84 so that his average is at least 88 given first two grades 82 and 98.
Learn more about averages here:
brainly.com/question/19004665
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