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Finding the Fourth Proportional to 109.20, 149.40 and 108.12

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Solution

The fourth proportional to 109.20, 149.40 and 108.12 is: 147.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.20 : 149.40 = 108.12 : x
  2. Step 2: Convert to fraction form
    109.20/149.40 = 108.12/x
  3. Step 3: Cross multiply
    109.20x = 149.40 × 108.12
  4. Step 4: Simplify right side
    109.20x = 16,153.13
  5. Step 5: Solve for x
    x = 16,153.13/109.20
  6. Step 6: Final answer
    x = 147.92

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.