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Finding the Fourth Proportional to 8.81, 13.20 and 6.90

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Solution

The fourth proportional to 8.81, 13.20 and 6.90 is: 10.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.81 : 13.20 = 6.90 : x
  2. Step 2: Convert to fraction form
    8.81/13.20 = 6.90/x
  3. Step 3: Cross multiply
    8.81x = 13.20 × 6.90
  4. Step 4: Simplify right side
    8.81x = 91.08
  5. Step 5: Solve for x
    x = 91.08/8.81
  6. Step 6: Final answer
    x = 10.34

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.