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Finding the Fourth Proportional to 128.10, 191.95 and 67.14

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Solution

The fourth proportional to 128.10, 191.95 and 67.14 is: 100.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.10 : 191.95 = 67.14 : x
  2. Step 2: Convert to fraction form
    128.10/191.95 = 67.14/x
  3. Step 3: Cross multiply
    128.10x = 191.95 × 67.14
  4. Step 4: Simplify right side
    128.10x = 12,887.52
  5. Step 5: Solve for x
    x = 12,887.52/128.10
  6. Step 6: Final answer
    x = 100.61

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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.