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Finding the Fourth Proportional to 12.85, 17.72 and 12.15

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Solution

The fourth proportional to 12.85, 17.72 and 12.15 is: 16.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.85 : 17.72 = 12.15 : x
  2. Step 2: Convert to fraction form
    12.85/17.72 = 12.15/x
  3. Step 3: Cross multiply
    12.85x = 17.72 × 12.15
  4. Step 4: Simplify right side
    12.85x = 215.28
  5. Step 5: Solve for x
    x = 215.28/12.85
  6. Step 6: Final answer
    x = 16.75

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.