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Finding the Fourth Proportional to 9.28, 12.80 and 9

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Solution

The fourth proportional to 9.28, 12.80 and 9 is: 12.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    9.28 : 12.80 = 9 : x
  2. Step 2: Convert to fraction form
    9.28/12.80 = 9/x
  3. Step 3: Cross multiply
    9.28x = 12.80 × 9
  4. Step 4: Simplify right side
    9.28x = 115.20
  5. Step 5: Solve for x
    x = 115.20/9.28
  6. Step 6: Final answer
    x = 12.41

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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.