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Finding the Fourth Proportional to 11.21, 16.72 and 9.78

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Solution

The fourth proportional to 11.21, 16.72 and 9.78 is: 14.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    11.21 : 16.72 = 9.78 : x
  2. Step 2: Convert to fraction form
    11.21/16.72 = 9.78/x
  3. Step 3: Cross multiply
    11.21x = 16.72 × 9.78
  4. Step 4: Simplify right side
    11.21x = 163.43
  5. Step 5: Solve for x
    x = 163.43/11.21
  6. Step 6: Final answer
    x = 14.59

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.