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Finding the Fourth Proportional to 78.92, 117.96 and 68.55

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Solution

The fourth proportional to 78.92, 117.96 and 68.55 is: 102.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.92 : 117.96 = 68.55 : x
  2. Step 2: Convert to fraction form
    78.92/117.96 = 68.55/x
  3. Step 3: Cross multiply
    78.92x = 117.96 × 68.55
  4. Step 4: Simplify right side
    78.92x = 8,086.86
  5. Step 5: Solve for x
    x = 8,086.86/78.92
  6. Step 6: Final answer
    x = 102.47

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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.