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Finding the Fourth Proportional to 8.39, 12.64 and 7.65

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Solution

The fourth proportional to 8.39, 12.64 and 7.65 is: 11.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    8.39 : 12.64 = 7.65 : x
  2. Step 2: Convert to fraction form
    8.39/12.64 = 7.65/x
  3. Step 3: Cross multiply
    8.39x = 12.64 × 7.65
  4. Step 4: Simplify right side
    8.39x = 96.59
  5. Step 5: Solve for x
    x = 96.59/8.39
  6. Step 6: Final answer
    x = 11.52

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.