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Finding the Fourth Proportional to 518.31, 715.29 and 308.61

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Solution

The fourth proportional to 518.31, 715.29 and 308.61 is: 425.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.31 : 715.29 = 308.61 : x
  2. Step 2: Convert to fraction form
    518.31/715.29 = 308.61/x
  3. Step 3: Cross multiply
    518.31x = 715.29 × 308.61
  4. Step 4: Simplify right side
    518.31x = 220,745.65
  5. Step 5: Solve for x
    x = 220,745.65/518.31
  6. Step 6: Final answer
    x = 425.90

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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.