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Finding the Fourth Proportional to 120.68, 180.84 and 90.11

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Solution

The fourth proportional to 120.68, 180.84 and 90.11 is: 135.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.68 : 180.84 = 90.11 : x
  2. Step 2: Convert to fraction form
    120.68/180.84 = 90.11/x
  3. Step 3: Cross multiply
    120.68x = 180.84 × 90.11
  4. Step 4: Simplify right side
    120.68x = 16,295.49
  5. Step 5: Solve for x
    x = 16,295.49/120.68
  6. Step 6: Final answer
    x = 135.03

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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.