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Finding the Fourth Proportional to 140.40, 210.81 and 129.69

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Solution

The fourth proportional to 140.40, 210.81 and 129.69 is: 194.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    140.40 : 210.81 = 129.69 : x
  2. Step 2: Convert to fraction form
    140.40/210.81 = 129.69/x
  3. Step 3: Cross multiply
    140.40x = 210.81 × 129.69
  4. Step 4: Simplify right side
    140.40x = 27,339.95
  5. Step 5: Solve for x
    x = 27,339.95/140.40
  6. Step 6: Final answer
    x = 194.73

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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.