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Finding the Fourth Proportional to 13.25, 18.29 and 7.80

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Solution

The fourth proportional to 13.25, 18.29 and 7.80 is: 10.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.25 : 18.29 = 7.80 : x
  2. Step 2: Convert to fraction form
    13.25/18.29 = 7.80/x
  3. Step 3: Cross multiply
    13.25x = 18.29 × 7.80
  4. Step 4: Simplify right side
    13.25x = 142.61
  5. Step 5: Solve for x
    x = 142.61/13.25
  6. Step 6: Final answer
    x = 10.76

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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.