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Finding the Fourth Proportional to 12.85, 17.72 and 8

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Solution

The fourth proportional to 12.85, 17.72 and 8 is: 11.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.85 : 17.72 = 8 : x
  2. Step 2: Convert to fraction form
    12.85/17.72 = 8/x
  3. Step 3: Cross multiply
    12.85x = 17.72 × 8
  4. Step 4: Simplify right side
    12.85x = 141.76
  5. Step 5: Solve for x
    x = 141.76/12.85
  6. Step 6: Final answer
    x = 11.03

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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.