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Finding the Fourth Proportional to 8.09, 11.15 and 7.70

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Solution

The fourth proportional to 8.09, 11.15 and 7.70 is: 10.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.09 : 11.15 = 7.70 : x
  2. Step 2: Convert to fraction form
    8.09/11.15 = 7.70/x
  3. Step 3: Cross multiply
    8.09x = 11.15 × 7.70
  4. Step 4: Simplify right side
    8.09x = 85.86
  5. Step 5: Solve for x
    x = 85.86/8.09
  6. Step 6: Final answer
    x = 10.61

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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.