Solve. Please show the algebraic inequality you used and show all of your work.
Stephanie has the following scores on her algebra tests: 85, 92, and 71. What score must she earn on her fourth test in order to have an average of 80 or above?
(85+92+71+x)/4 ≥ 80
Solve for x.
1.2
x>=4*80-85-92-71=320-85-92-71=320-248=72
To find out the score Stephanie must earn on her fourth test to have an average of 80 or above, we can set up an inequality and solve it.
Let x represent Stephanie's score on her fourth test.
To calculate the average of her four tests, we add up all the scores and then divide by 4:
(85 + 92 + 71 + x)/4 ≥ 80
Now, we can simplify and solve the inequality step by step:
(85 + 92 + 71 + x)/4 ≥ 80
(248 + x)/4 ≥ 80
Multiplying both sides by 4 to remove the denominator:
248 + x ≥ 320
Subtracting 248 from both sides:
x ≥ 320 - 248
x ≥ 72
Therefore, Stephanie must earn a score of 72 or higher on her fourth test in order to have an average of 80 or above.