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Finding the Fourth Proportional to 518.59, 715.59 and 308.78

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Solution

The fourth proportional to 518.59, 715.59 and 308.78 is: 426.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.59 : 715.59 = 308.78 : x
  2. Step 2: Convert to fraction form
    518.59/715.59 = 308.78/x
  3. Step 3: Cross multiply
    518.59x = 715.59 × 308.78
  4. Step 4: Simplify right side
    518.59x = 220,959.88
  5. Step 5: Solve for x
    x = 220,959.88/518.59
  6. Step 6: Final answer
    x = 426.08

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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.