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Finding the Fourth Proportional to 638.64, 881.08 and 389.84

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Solution

The fourth proportional to 638.64, 881.08 and 389.84 is: 537.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.64 : 881.08 = 389.84 : x
  2. Step 2: Convert to fraction form
    638.64/881.08 = 389.84/x
  3. Step 3: Cross multiply
    638.64x = 881.08 × 389.84
  4. Step 4: Simplify right side
    638.64x = 343,480.23
  5. Step 5: Solve for x
    x = 343,480.23/638.64
  6. Step 6: Final answer
    x = 537.83

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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.