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Finding the Fourth Proportional to 140.28, 209.79 and 128.94

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Solution

The fourth proportional to 140.28, 209.79 and 128.94 is: 192.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.28 : 209.79 = 128.94 : x
  2. Step 2: Convert to fraction form
    140.28/209.79 = 128.94/x
  3. Step 3: Cross multiply
    140.28x = 209.79 × 128.94
  4. Step 4: Simplify right side
    140.28x = 27,050.32
  5. Step 5: Solve for x
    x = 27,050.32/140.28
  6. Step 6: Final answer
    x = 192.83

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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.