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Finding the Fourth Proportional to 638.60, 881.33 and 386.60

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Solution

The fourth proportional to 638.60, 881.33 and 386.60 is: 533.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.60 : 881.33 = 386.60 : x
  2. Step 2: Convert to fraction form
    638.60/881.33 = 386.60/x
  3. Step 3: Cross multiply
    638.60x = 881.33 × 386.60
  4. Step 4: Simplify right side
    638.60x = 340,720.49
  5. Step 5: Solve for x
    x = 340,720.49/638.60
  6. Step 6: Final answer
    x = 533.55

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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.