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Finding the Third Proportional to 139.85 and 210.09

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Solution

The third proportional to 139.85 and 210.09 is: 315.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.85 : 210.09 = 210.09 : x
  2. Step 2: Convert to fraction form
    139.85/210.09 = 210.09/x
  3. Step 3: Cross multiply
    139.85x = 210.09 × 210.09
  4. Step 4: Simplify right side
    139.85x = 44,139.38
  5. Step 5: Solve for x
    x = 44,139.38/139.85
  6. Step 6: Final answer
    x = 315.62

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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.