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Finding the Fourth Proportional to 8.60, 12.88 and 6.90

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Solution

The fourth proportional to 8.60, 12.88 and 6.90 is: 10.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.60 : 12.88 = 6.90 : x
  2. Step 2: Convert to fraction form
    8.60/12.88 = 6.90/x
  3. Step 3: Cross multiply
    8.60x = 12.88 × 6.90
  4. Step 4: Simplify right side
    8.60x = 88.87
  5. Step 5: Solve for x
    x = 88.87/8.60
  6. Step 6: Final answer
    x = 10.33

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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.