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Finding the Fourth Proportional to 520.28, 717.92 and 287.40

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Solution

The fourth proportional to 520.28, 717.92 and 287.40 is: 396.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.28 : 717.92 = 287.40 : x
  2. Step 2: Convert to fraction form
    520.28/717.92 = 287.40/x
  3. Step 3: Cross multiply
    520.28x = 717.92 × 287.40
  4. Step 4: Simplify right side
    520.28x = 206,330.21
  5. Step 5: Solve for x
    x = 206,330.21/520.28
  6. Step 6: Final answer
    x = 396.58

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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.