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Finding the Fourth Proportional to 8.47, 12.66 and 6.21

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Solution

The fourth proportional to 8.47, 12.66 and 6.21 is: 9.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.47 : 12.66 = 6.21 : x
  2. Step 2: Convert to fraction form
    8.47/12.66 = 6.21/x
  3. Step 3: Cross multiply
    8.47x = 12.66 × 6.21
  4. Step 4: Simplify right side
    8.47x = 78.60
  5. Step 5: Solve for x
    x = 78.60/8.47
  6. Step 6: Final answer
    x = 9.28

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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.