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Finding the Fourth Proportional to 90.05, 135.19 and 77.84

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Solution

The fourth proportional to 90.05, 135.19 and 77.84 is: 116.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.05 : 135.19 = 77.84 : x
  2. Step 2: Convert to fraction form
    90.05/135.19 = 77.84/x
  3. Step 3: Cross multiply
    90.05x = 135.19 × 77.84
  4. Step 4: Simplify right side
    90.05x = 10,523.12
  5. Step 5: Solve for x
    x = 10,523.12/90.05
  6. Step 6: Final answer
    x = 116.87

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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.