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Finding the Fourth Proportional to 90.61, 135.61 and 82.18

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Solution

The fourth proportional to 90.61, 135.61 and 82.18 is: 122.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.61 : 135.61 = 82.18 : x
  2. Step 2: Convert to fraction form
    90.61/135.61 = 82.18/x
  3. Step 3: Cross multiply
    90.61x = 135.61 × 82.18
  4. Step 4: Simplify right side
    90.61x = 11,144.43
  5. Step 5: Solve for x
    x = 11,144.43/90.61
  6. Step 6: Final answer
    x = 122.99

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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.