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Finding the Fourth Proportional to 638.43, 881.43 and 490.77

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Solution

The fourth proportional to 638.43, 881.43 and 490.77 is: 677.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.43 : 881.43 = 490.77 : x
  2. Step 2: Convert to fraction form
    638.43/881.43 = 490.77/x
  3. Step 3: Cross multiply
    638.43x = 881.43 × 490.77
  4. Step 4: Simplify right side
    638.43x = 432,579.40
  5. Step 5: Solve for x
    x = 432,579.40/638.43
  6. Step 6: Final answer
    x = 677.57

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Double scale
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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.