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Finding the Fourth Proportional to 11.40, 17.09 and 8.72

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Solution

The fourth proportional to 11.40, 17.09 and 8.72 is: 13.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    11.40 : 17.09 = 8.72 : x
  2. Step 2: Convert to fraction form
    11.40/17.09 = 8.72/x
  3. Step 3: Cross multiply
    11.40x = 17.09 × 8.72
  4. Step 4: Simplify right side
    11.40x = 148.90
  5. Step 5: Solve for x
    x = 148.90/11.40
  6. Step 6: Final answer
    x = 13.06

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.