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Finding the Fourth Proportional to 12.45, 17.16 and 9.21

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Solution

The fourth proportional to 12.45, 17.16 and 9.21 is: 12.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.45 : 17.16 = 9.21 : x
  2. Step 2: Convert to fraction form
    12.45/17.16 = 9.21/x
  3. Step 3: Cross multiply
    12.45x = 17.16 × 9.21
  4. Step 4: Simplify right side
    12.45x = 157.96
  5. Step 5: Solve for x
    x = 157.96/12.45
  6. Step 6: Final answer
    x = 12.69

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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.