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Finding the Fourth Proportional to 739.85, 1,109.78 and 415.21

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Solution

The fourth proportional to 739.85, 1,109.78 and 415.21 is: 622.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    739.85 : 1,109.78 = 415.21 : x
  2. Step 2: Convert to fraction form
    739.85/1,109.78 = 415.21/x
  3. Step 3: Cross multiply
    739.85x = 1,109.78 × 415.21
  4. Step 4: Simplify right side
    739.85x = 460,789.68
  5. Step 5: Solve for x
    x = 460,789.68/739.85
  6. Step 6: Final answer
    x = 622.82

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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.