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Finding the Fourth Proportional to 813.14, 1,218.39 and 487.70

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Solution

The fourth proportional to 813.14, 1,218.39 and 487.70 is: 730.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    813.14 : 1,218.39 = 487.70 : x
  2. Step 2: Convert to fraction form
    813.14/1,218.39 = 487.70/x
  3. Step 3: Cross multiply
    813.14x = 1,218.39 × 487.70
  4. Step 4: Simplify right side
    813.14x = 594,208.80
  5. Step 5: Solve for x
    x = 594,208.80/813.14
  6. Step 6: Final answer
    x = 730.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.