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Finding the Fourth Proportional to 638.77, 881.48 and 355.18

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Solution

The fourth proportional to 638.77, 881.48 and 355.18 is: 490.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.77 : 881.48 = 355.18 : x
  2. Step 2: Convert to fraction form
    638.77/881.48 = 355.18/x
  3. Step 3: Cross multiply
    638.77x = 881.48 × 355.18
  4. Step 4: Simplify right side
    638.77x = 313,083.18
  5. Step 5: Solve for x
    x = 313,083.18/638.77
  6. Step 6: Final answer
    x = 490.13

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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.