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Finding the Fourth Proportional to 90.21, 135.27 and 54.12

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Solution

The fourth proportional to 90.21, 135.27 and 54.12 is: 81.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.21 : 135.27 = 54.12 : x
  2. Step 2: Convert to fraction form
    90.21/135.27 = 54.12/x
  3. Step 3: Cross multiply
    90.21x = 135.27 × 54.12
  4. Step 4: Simplify right side
    90.21x = 7,320.81
  5. Step 5: Solve for x
    x = 7,320.81/90.21
  6. Step 6: Final answer
    x = 81.15

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These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.