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Finding the Fourth Proportional to 551.50, 761.10 and 318.70

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Solution

The fourth proportional to 551.50, 761.10 and 318.70 is: 439.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    551.50 : 761.10 = 318.70 : x
  2. Step 2: Convert to fraction form
    551.50/761.10 = 318.70/x
  3. Step 3: Cross multiply
    551.50x = 761.10 × 318.70
  4. Step 4: Simplify right side
    551.50x = 242,562.57
  5. Step 5: Solve for x
    x = 242,562.57/551.50
  6. Step 6: Final answer
    x = 439.82

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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.