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Finding the Fourth Proportional to 90.02, 135.17 and 85.44

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Solution

The fourth proportional to 90.02, 135.17 and 85.44 is: 128.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.02 : 135.17 = 85.44 : x
  2. Step 2: Convert to fraction form
    90.02/135.17 = 85.44/x
  3. Step 3: Cross multiply
    90.02x = 135.17 × 85.44
  4. Step 4: Simplify right side
    90.02x = 11,548.50
  5. Step 5: Solve for x
    x = 11,548.50/90.02
  6. Step 6: Final answer
    x = 128.30

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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.