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Finding the Fourth Proportional to 9.21, 12.72 and 7.17

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Solution

The fourth proportional to 9.21, 12.72 and 7.17 is: 9.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.21 : 12.72 = 7.17 : x
  2. Step 2: Convert to fraction form
    9.21/12.72 = 7.17/x
  3. Step 3: Cross multiply
    9.21x = 12.72 × 7.17
  4. Step 4: Simplify right side
    9.21x = 91.18
  5. Step 5: Solve for x
    x = 91.18/9.21
  6. Step 6: Final answer
    x = 9.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.