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Finding the Fourth Proportional to 217.47, 300.12 and 128.94

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Solution

The fourth proportional to 217.47, 300.12 and 128.94 is: 177.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.47 : 300.12 = 128.94 : x
  2. Step 2: Convert to fraction form
    217.47/300.12 = 128.94/x
  3. Step 3: Cross multiply
    217.47x = 300.12 × 128.94
  4. Step 4: Simplify right side
    217.47x = 38,697.47
  5. Step 5: Solve for x
    x = 38,697.47/217.47
  6. Step 6: Final answer
    x = 177.94

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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.