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Finding the Fourth Proportional to 426.23, 639.21 and 137.60

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Solution

The fourth proportional to 426.23, 639.21 and 137.60 is: 206.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.23 : 639.21 = 137.60 : x
  2. Step 2: Convert to fraction form
    426.23/639.21 = 137.60/x
  3. Step 3: Cross multiply
    426.23x = 639.21 × 137.60
  4. Step 4: Simplify right side
    426.23x = 87,956.04
  5. Step 5: Solve for x
    x = 87,956.04/426.23
  6. Step 6: Final answer
    x = 206.36

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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.