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Finding the Fourth Proportional to 78.82, 117.82 and 68.11

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Solution

The fourth proportional to 78.82, 117.82 and 68.11 is: 101.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.82 : 117.82 = 68.11 : x
  2. Step 2: Convert to fraction form
    78.82/117.82 = 68.11/x
  3. Step 3: Cross multiply
    78.82x = 117.82 × 68.11
  4. Step 4: Simplify right side
    78.82x = 8,024.89
  5. Step 5: Solve for x
    x = 8,024.89/78.82
  6. Step 6: Final answer
    x = 101.81

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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.