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Finding the Fourth Proportional to 638.19, 880.79 and 389.54

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Solution

The fourth proportional to 638.19, 880.79 and 389.54 is: 537.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.19 : 880.79 = 389.54 : x
  2. Step 2: Convert to fraction form
    638.19/880.79 = 389.54/x
  3. Step 3: Cross multiply
    638.19x = 880.79 × 389.54
  4. Step 4: Simplify right side
    638.19x = 343,103.19
  5. Step 5: Solve for x
    x = 343,103.19/638.19
  6. Step 6: Final answer
    x = 537.62

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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.