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Finding the Fourth Proportional to 6.90, 10.38 and 6.78

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Solution

The fourth proportional to 6.90, 10.38 and 6.78 is: 10.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.90 : 10.38 = 6.78 : x
  2. Step 2: Convert to fraction form
    6.90/10.38 = 6.78/x
  3. Step 3: Cross multiply
    6.90x = 10.38 × 6.78
  4. Step 4: Simplify right side
    6.90x = 70.38
  5. Step 5: Solve for x
    x = 70.38/6.90
  6. Step 6: Final answer
    x = 10.20

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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.