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Finding the Fourth Proportional to 137.64, 206.28 and 86.16

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Solution

The fourth proportional to 137.64, 206.28 and 86.16 is: 129.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.64 : 206.28 = 86.16 : x
  2. Step 2: Convert to fraction form
    137.64/206.28 = 86.16/x
  3. Step 3: Cross multiply
    137.64x = 206.28 × 86.16
  4. Step 4: Simplify right side
    137.64x = 17,773.08
  5. Step 5: Solve for x
    x = 17,773.08/137.64
  6. Step 6: Final answer
    x = 129.13

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.