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Finding the Third Proportional to 30.85 and 47.09

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Solution

The third proportional to 30.85 and 47.09 is: 71.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.85 : 47.09 = 47.09 : x
  2. Step 2: Convert to fraction form
    30.85/47.09 = 47.09/x
  3. Step 3: Cross multiply
    30.85x = 47.09 × 47.09
  4. Step 4: Simplify right side
    30.85x = 2,217.64
  5. Step 5: Solve for x
    x = 2,217.64/30.85
  6. Step 6: Final answer
    x = 71.89

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Why These Related Problems?

These problems maintain the same ratio (1.53) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.