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Finding the Fourth Proportional to 521.91, 782.42 and 261.55

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Solution

The fourth proportional to 521.91, 782.42 and 261.55 is: 392.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.91 : 782.42 = 261.55 : x
  2. Step 2: Convert to fraction form
    521.91/782.42 = 261.55/x
  3. Step 3: Cross multiply
    521.91x = 782.42 × 261.55
  4. Step 4: Simplify right side
    521.91x = 204,640.64
  5. Step 5: Solve for x
    x = 204,640.64/521.91
  6. Step 6: Final answer
    x = 392.10

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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.