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Finding the Fourth Proportional to 139.31, 208.97 and 43.13

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Solution

The fourth proportional to 139.31, 208.97 and 43.13 is: 64.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.31 : 208.97 = 43.13 : x
  2. Step 2: Convert to fraction form
    139.31/208.97 = 43.13/x
  3. Step 3: Cross multiply
    139.31x = 208.97 × 43.13
  4. Step 4: Simplify right side
    139.31x = 9,011.94
  5. Step 5: Solve for x
    x = 9,011.94/139.31
  6. Step 6: Final answer
    x = 64.69

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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.