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Finding the Fourth Proportional to 820.11, 1,229.39 and 299.70

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Solution

The fourth proportional to 820.11, 1,229.39 and 299.70 is: 449.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    820.11 : 1,229.39 = 299.70 : x
  2. Step 2: Convert to fraction form
    820.11/1,229.39 = 299.70/x
  3. Step 3: Cross multiply
    820.11x = 1,229.39 × 299.70
  4. Step 4: Simplify right side
    820.11x = 368,446.68
  5. Step 5: Solve for x
    x = 368,446.68/820.11
  6. Step 6: Final answer
    x = 449.26

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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.