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Finding the Fourth Proportional to 518.30, 715.25 and 285.42

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Solution

The fourth proportional to 518.30, 715.25 and 285.42 is: 393.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.30 : 715.25 = 285.42 : x
  2. Step 2: Convert to fraction form
    518.30/715.25 = 285.42/x
  3. Step 3: Cross multiply
    518.30x = 715.25 × 285.42
  4. Step 4: Simplify right side
    518.30x = 204,148.98
  5. Step 5: Solve for x
    x = 204,148.98/518.30
  6. Step 6: Final answer
    x = 393.88

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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.