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Finding the Fourth Proportional to 9.72, 13.40 and 6.81

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Solution

The fourth proportional to 9.72, 13.40 and 6.81 is: 9.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.72 : 13.40 = 6.81 : x
  2. Step 2: Convert to fraction form
    9.72/13.40 = 6.81/x
  3. Step 3: Cross multiply
    9.72x = 13.40 × 6.81
  4. Step 4: Simplify right side
    9.72x = 91.25
  5. Step 5: Solve for x
    x = 91.25/9.72
  6. Step 6: Final answer
    x = 9.39

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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.