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Finding the Fourth Proportional to 638.28, 881.28 and 556.47

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Solution

The fourth proportional to 638.28, 881.28 and 556.47 is: 768.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.28 : 881.28 = 556.47 : x
  2. Step 2: Convert to fraction form
    638.28/881.28 = 556.47/x
  3. Step 3: Cross multiply
    638.28x = 881.28 × 556.47
  4. Step 4: Simplify right side
    638.28x = 490,405.88
  5. Step 5: Solve for x
    x = 490,405.88/638.28
  6. Step 6: Final answer
    x = 768.32

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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.