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Finding the Fourth Proportional to 638.22, 880.70 and 389.55

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Solution

The fourth proportional to 638.22, 880.70 and 389.55 is: 537.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.22 : 880.70 = 389.55 : x
  2. Step 2: Convert to fraction form
    638.22/880.70 = 389.55/x
  3. Step 3: Cross multiply
    638.22x = 880.70 × 389.55
  4. Step 4: Simplify right side
    638.22x = 343,076.69
  5. Step 5: Solve for x
    x = 343,076.69/638.22
  6. Step 6: Final answer
    x = 537.55

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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.