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Finding the Fourth Proportional to 77.71, 107.15 and 63.69

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Solution

The fourth proportional to 77.71, 107.15 and 63.69 is: 87.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.71 : 107.15 = 63.69 : x
  2. Step 2: Convert to fraction form
    77.71/107.15 = 63.69/x
  3. Step 3: Cross multiply
    77.71x = 107.15 × 63.69
  4. Step 4: Simplify right side
    77.71x = 6,824.38
  5. Step 5: Solve for x
    x = 6,824.38/77.71
  6. Step 6: Final answer
    x = 87.82

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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.