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Finding the Fourth Proportional to 518.40, 714.96 and 387.72

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Solution

The fourth proportional to 518.40, 714.96 and 387.72 is: 534.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.40 : 714.96 = 387.72 : x
  2. Step 2: Convert to fraction form
    518.40/714.96 = 387.72/x
  3. Step 3: Cross multiply
    518.40x = 714.96 × 387.72
  4. Step 4: Simplify right side
    518.40x = 277,204.29
  5. Step 5: Solve for x
    x = 277,204.29/518.40
  6. Step 6: Final answer
    x = 534.73

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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.