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Finding the Fourth Proportional to 515.72, 711.88 and 308.72

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Solution

The fourth proportional to 515.72, 711.88 and 308.72 is: 426.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.72 : 711.88 = 308.72 : x
  2. Step 2: Convert to fraction form
    515.72/711.88 = 308.72/x
  3. Step 3: Cross multiply
    515.72x = 711.88 × 308.72
  4. Step 4: Simplify right side
    515.72x = 219,772.60
  5. Step 5: Solve for x
    x = 219,772.60/515.72
  6. Step 6: Final answer
    x = 426.15

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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.