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Finding the Fourth Proportional to 7.69, 11.51 and 5.15

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Solution

The fourth proportional to 7.69, 11.51 and 5.15 is: 7.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.69 : 11.51 = 5.15 : x
  2. Step 2: Convert to fraction form
    7.69/11.51 = 5.15/x
  3. Step 3: Cross multiply
    7.69x = 11.51 × 5.15
  4. Step 4: Simplify right side
    7.69x = 59.28
  5. Step 5: Solve for x
    x = 59.28/7.69
  6. Step 6: Final answer
    x = 7.71

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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.