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Finding the Fourth Proportional to 801.20, 1,105.65 and 490.70

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Solution

The fourth proportional to 801.20, 1,105.65 and 490.70 is: 677.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.20 : 1,105.65 = 490.70 : x
  2. Step 2: Convert to fraction form
    801.20/1,105.65 = 490.70/x
  3. Step 3: Cross multiply
    801.20x = 1,105.65 × 490.70
  4. Step 4: Simplify right side
    801.20x = 542,536.93
  5. Step 5: Solve for x
    x = 542,536.93/801.20
  6. Step 6: Final answer
    x = 677.16

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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.