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Finding the Fourth Proportional to 218.40, 301.35 and 129.88

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Solution

The fourth proportional to 218.40, 301.35 and 129.88 is: 179.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.40 : 301.35 = 129.88 : x
  2. Step 2: Convert to fraction form
    218.40/301.35 = 129.88/x
  3. Step 3: Cross multiply
    218.40x = 301.35 × 129.88
  4. Step 4: Simplify right side
    218.40x = 39,138.26
  5. Step 5: Solve for x
    x = 39,138.26/218.40
  6. Step 6: Final answer
    x = 179.21

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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.