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Finding the Fourth Proportional to 78.35, 117.39 and 68.14

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Solution

The fourth proportional to 78.35, 117.39 and 68.14 is: 102.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.35 : 117.39 = 68.14 : x
  2. Step 2: Convert to fraction form
    78.35/117.39 = 68.14/x
  3. Step 3: Cross multiply
    78.35x = 117.39 × 68.14
  4. Step 4: Simplify right side
    78.35x = 7,998.95
  5. Step 5: Solve for x
    x = 7,998.95/78.35
  6. Step 6: Final answer
    x = 102.09

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.