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Finding the Fourth Proportional to 6.90, 10.29 and 6.65

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Solution

The fourth proportional to 6.90, 10.29 and 6.65 is: 9.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    6.90 : 10.29 = 6.65 : x
  2. Step 2: Convert to fraction form
    6.90/10.29 = 6.65/x
  3. Step 3: Cross multiply
    6.90x = 10.29 × 6.65
  4. Step 4: Simplify right side
    6.90x = 68.38
  5. Step 5: Solve for x
    x = 68.38/6.90
  6. Step 6: Final answer
    x = 9.91

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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.