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Finding the Fourth Proportional to 78.87, 117.75 and 68.61

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Solution

The fourth proportional to 78.87, 117.75 and 68.61 is: 102.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.87 : 117.75 = 68.61 : x
  2. Step 2: Convert to fraction form
    78.87/117.75 = 68.61/x
  3. Step 3: Cross multiply
    78.87x = 117.75 × 68.61
  4. Step 4: Simplify right side
    78.87x = 8,078.83
  5. Step 5: Solve for x
    x = 8,078.83/78.87
  6. Step 6: Final answer
    x = 102.43

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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.