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Finding the Fourth Proportional to 122.78, 184.38 and 90.38

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Solution

The fourth proportional to 122.78, 184.38 and 90.38 is: 135.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.78 : 184.38 = 90.38 : x
  2. Step 2: Convert to fraction form
    122.78/184.38 = 90.38/x
  3. Step 3: Cross multiply
    122.78x = 184.38 × 90.38
  4. Step 4: Simplify right side
    122.78x = 16,664.26
  5. Step 5: Solve for x
    x = 16,664.26/122.78
  6. Step 6: Final answer
    x = 135.72

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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.