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Finding the Fourth Proportional to 85.76, 127.96 and 68.56

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Solution

The fourth proportional to 85.76, 127.96 and 68.56 is: 102.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.76 : 127.96 = 68.56 : x
  2. Step 2: Convert to fraction form
    85.76/127.96 = 68.56/x
  3. Step 3: Cross multiply
    85.76x = 127.96 × 68.56
  4. Step 4: Simplify right side
    85.76x = 8,772.94
  5. Step 5: Solve for x
    x = 8,772.94/85.76
  6. Step 6: Final answer
    x = 102.30

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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.