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Finding the Fourth Proportional to 8.67, 13.02 and 7.80

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Solution

The fourth proportional to 8.67, 13.02 and 7.80 is: 11.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.67 : 13.02 = 7.80 : x
  2. Step 2: Convert to fraction form
    8.67/13.02 = 7.80/x
  3. Step 3: Cross multiply
    8.67x = 13.02 × 7.80
  4. Step 4: Simplify right side
    8.67x = 101.56
  5. Step 5: Solve for x
    x = 101.56/8.67
  6. Step 6: Final answer
    x = 11.71

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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.