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Finding the Third Proportional to 2.85 and 7.85

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Solution

The third proportional to 2.85 and 7.85 is: 21.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    2.85 : 7.85 = 7.85 : x
  2. Step 2: Convert to fraction form
    2.85/7.85 = 7.85/x
  3. Step 3: Cross multiply
    2.85x = 7.85 × 7.85
  4. Step 4: Simplify right side
    2.85x = 61.58
  5. Step 5: Solve for x
    x = 61.58/2.85
  6. Step 6: Final answer
    x = 21.58

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Why These Related Problems?

These problems maintain the same ratio (2.75) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.