SOLUTION: Write and solve an inequality.
School: Logan earned these scores on the first three tests in biology this term: 86, 88, and 78. What is the lowest score that Logan can earn on the
Algebra ->
Inequalities
-> SOLUTION: Write and solve an inequality.
School: Logan earned these scores on the first three tests in biology this term: 86, 88, and 78. What is the lowest score that Logan can earn on the
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Question 1171147: Write and solve an inequality.
School: Logan earned these scores on the first three tests in biology this term: 86, 88, and 78. What is the lowest score that Logan can earn on the fourth and final test of the term if he wants to have an average of at least 83?
(86 + 88 + 78 + x) / 4 >= 83
simplify to get:
(252 + x) / 4 >= 83
multiply both sides of this inequality by 4 to get:
252 + x >= 332
subtract 252 from both sides of the inequality to get:
x >= 332 - 252
solve for x to get:
x >= 80.
logan needs to get at least an 80 to bet an average of at least 83.
to confirm, replace x in the equation with 80 to get:
you get:
(86 + 88 + 78 + 80) / 4 >= 83
simplify to get:
(332 / 4 >= 83 which becomes 83 >= 83.
this confirms the solution is correct.
when x = 80, the average equals 83.
when x > 80, the average is greater than 83.
