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Finding the Fourth Proportional to 120.86, 180.66 and 90.14

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Solution

The fourth proportional to 120.86, 180.66 and 90.14 is: 134.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.86 : 180.66 = 90.14 : x
  2. Step 2: Convert to fraction form
    120.86/180.66 = 90.14/x
  3. Step 3: Cross multiply
    120.86x = 180.66 × 90.14
  4. Step 4: Simplify right side
    120.86x = 16,284.69
  5. Step 5: Solve for x
    x = 16,284.69/120.86
  6. Step 6: Final answer
    x = 134.74

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.