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Finding the Fourth Proportional to 6.85, 10.22 and 5.15

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Solution

The fourth proportional to 6.85, 10.22 and 5.15 is: 7.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.85 : 10.22 = 5.15 : x
  2. Step 2: Convert to fraction form
    6.85/10.22 = 5.15/x
  3. Step 3: Cross multiply
    6.85x = 10.22 × 5.15
  4. Step 4: Simplify right side
    6.85x = 52.59
  5. Step 5: Solve for x
    x = 52.59/6.85
  6. Step 6: Final answer
    x = 7.68

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.