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Finding the Fourth Proportional to 154.40, 212.03 and 129.80

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Solution

The fourth proportional to 154.40, 212.03 and 129.80 is: 178.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.40 : 212.03 = 129.80 : x
  2. Step 2: Convert to fraction form
    154.40/212.03 = 129.80/x
  3. Step 3: Cross multiply
    154.40x = 212.03 × 129.80
  4. Step 4: Simplify right side
    154.40x = 27,520.43
  5. Step 5: Solve for x
    x = 27,520.43/154.40
  6. Step 6: Final answer
    x = 178.24

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.