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Finding the Fourth Proportional to 426.25, 639.38 and 122.25

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Solution

The fourth proportional to 426.25, 639.38 and 122.25 is: 183.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.25 : 639.38 = 122.25 : x
  2. Step 2: Convert to fraction form
    426.25/639.38 = 122.25/x
  3. Step 3: Cross multiply
    426.25x = 639.38 × 122.25
  4. Step 4: Simplify right side
    426.25x = 78,163.59
  5. Step 5: Solve for x
    x = 78,163.59/426.25
  6. Step 6: Final answer
    x = 183.38

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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.