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Finding the Fourth Proportional to 7.87, 11.71 and 7.83

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Solution

The fourth proportional to 7.87, 11.71 and 7.83 is: 11.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    7.87 : 11.71 = 7.83 : x
  2. Step 2: Convert to fraction form
    7.87/11.71 = 7.83/x
  3. Step 3: Cross multiply
    7.87x = 11.71 × 7.83
  4. Step 4: Simplify right side
    7.87x = 91.69
  5. Step 5: Solve for x
    x = 91.69/7.87
  6. Step 6: Final answer
    x = 11.65

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.