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Finding the Fourth Proportional to 13.77, 20.64 and 6.90

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Solution

The fourth proportional to 13.77, 20.64 and 6.90 is: 10.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.77 : 20.64 = 6.90 : x
  2. Step 2: Convert to fraction form
    13.77/20.64 = 6.90/x
  3. Step 3: Cross multiply
    13.77x = 20.64 × 6.90
  4. Step 4: Simplify right side
    13.77x = 142.42
  5. Step 5: Solve for x
    x = 142.42/13.77
  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.