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Finding the Fourth Proportional to 127.13, 189.18 and 120.78

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Solution

The fourth proportional to 127.13, 189.18 and 120.78 is: 179.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    127.13 : 189.18 = 120.78 : x
  2. Step 2: Convert to fraction form
    127.13/189.18 = 120.78/x
  3. Step 3: Cross multiply
    127.13x = 189.18 × 120.78
  4. Step 4: Simplify right side
    127.13x = 22,849.16
  5. Step 5: Solve for x
    x = 22,849.16/127.13
  6. Step 6: Final answer
    x = 179.74

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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.