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Finding the Fourth Proportional to 13.22, 19.85 and 6.47

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Solution

The fourth proportional to 13.22, 19.85 and 6.47 is: 9.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.22 : 19.85 = 6.47 : x
  2. Step 2: Convert to fraction form
    13.22/19.85 = 6.47/x
  3. Step 3: Cross multiply
    13.22x = 19.85 × 6.47
  4. Step 4: Simplify right side
    13.22x = 128.30
  5. Step 5: Solve for x
    x = 128.30/13.22
  6. Step 6: Final answer
    x = 9.70

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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.