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Finding the Fourth Proportional to 13.24, 19.81 and 7.90

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Solution

The fourth proportional to 13.24, 19.81 and 7.90 is: 11.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.24 : 19.81 = 7.90 : x
  2. Step 2: Convert to fraction form
    13.24/19.81 = 7.90/x
  3. Step 3: Cross multiply
    13.24x = 19.81 × 7.90
  4. Step 4: Simplify right side
    13.24x = 156.46
  5. Step 5: Solve for x
    x = 156.46/13.24
  6. Step 6: Final answer
    x = 11.82

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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.