Answer: |x - 17.375| ≤ 1.125
Explanation:
1) Write the constraints in form of two inequalities, using x as variable name:
i) A maximum of 18.5 oz: x ≤ 18.5
ii) A minimum of 16.25 oz: x ≥ 16.25
2) Write as a combined inequality: 16.25 ≤ x ≤ 18.5
3) Find the midpoint between the two extremes:
(18.5 + 16.25) / 2 = 17.375
4) Subtract the midpoint from the three parts of the combined inequality:
16.25 - 17.375 ≤ x - 17.375 ≤ 18.5 - 17.375
-1.125 ≤ x - 17.375 ≤ 1.125
5) Use the property of absolute value inequality: | x - a| ≤ z ⇔ - z ≤ |x - a| ≤ z
-1.125 ≤ x - 17.375 ≤ 1.125 ⇔ |x - 17.375| ≤ 1.125
And that is the answer: |x - 17.375| ≤ 1.125
