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Finding the Fourth Proportional to 111.70, 154.19 and 80.21

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Solution

The fourth proportional to 111.70, 154.19 and 80.21 is: 110.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    111.70 : 154.19 = 80.21 : x
  2. Step 2: Convert to fraction form
    111.70/154.19 = 80.21/x
  3. Step 3: Cross multiply
    111.70x = 154.19 × 80.21
  4. Step 4: Simplify right side
    111.70x = 12,367.58
  5. Step 5: Solve for x
    x = 12,367.58/111.70
  6. Step 6: Final answer
    x = 110.72

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.