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Finding the Fourth Proportional to 12.75, 17.58 and 7.21

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Solution

The fourth proportional to 12.75, 17.58 and 7.21 is: 9.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.75 : 17.58 = 7.21 : x
  2. Step 2: Convert to fraction form
    12.75/17.58 = 7.21/x
  3. Step 3: Cross multiply
    12.75x = 17.58 × 7.21
  4. Step 4: Simplify right side
    12.75x = 126.83
  5. Step 5: Solve for x
    x = 126.83/12.75
  6. Step 6: Final answer
    x = 9.95

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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.