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Finding the Third Proportional to 71.34 and 78.09

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Solution

The third proportional to 71.34 and 78.09 is: 85.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.34 : 78.09 = 78.09 : x
  2. Step 2: Convert to fraction form
    71.34/78.09 = 78.09/x
  3. Step 3: Cross multiply
    71.34x = 78.09 × 78.09
  4. Step 4: Simplify right side
    71.34x = 6,098.63
  5. Step 5: Solve for x
    x = 6,098.63/71.34
  6. Step 6: Final answer
    x = 85.48

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Why These Related Problems?

These problems maintain the same ratio (1.09) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.