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Finding the Fourth Proportional to 17.21, 25.79 and 11.78

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Solution

The fourth proportional to 17.21, 25.79 and 11.78 is: 17.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    17.21 : 25.79 = 11.78 : x
  2. Step 2: Convert to fraction form
    17.21/25.79 = 11.78/x
  3. Step 3: Cross multiply
    17.21x = 25.79 × 11.78
  4. Step 4: Simplify right side
    17.21x = 303.81
  5. Step 5: Solve for x
    x = 303.81/17.21
  6. Step 6: Final answer
    x = 17.65

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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.