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Finding the Fourth Proportional to 518.86, 715.71 and 308.90

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Solution

The fourth proportional to 518.86, 715.71 and 308.90 is: 426.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.86 : 715.71 = 308.90 : x
  2. Step 2: Convert to fraction form
    518.86/715.71 = 308.90/x
  3. Step 3: Cross multiply
    518.86x = 715.71 × 308.90
  4. Step 4: Simplify right side
    518.86x = 221,081.74
  5. Step 5: Solve for x
    x = 221,081.74/518.86
  6. Step 6: Final answer
    x = 426.09

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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.