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Finding the Fourth Proportional to 425.81, 638.76 and 220.55

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Solution

The fourth proportional to 425.81, 638.76 and 220.55 is: 330.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.81 : 638.76 = 220.55 : x
  2. Step 2: Convert to fraction form
    425.81/638.76 = 220.55/x
  3. Step 3: Cross multiply
    425.81x = 638.76 × 220.55
  4. Step 4: Simplify right side
    425.81x = 140,875.32
  5. Step 5: Solve for x
    x = 140,875.32/425.81
  6. Step 6: Final answer
    x = 330.84

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.