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Finding the Fourth Proportional to 103.14, 154.08 and 78.84

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Solution

The fourth proportional to 103.14, 154.08 and 78.84 is: 117.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.14 : 154.08 = 78.84 : x
  2. Step 2: Convert to fraction form
    103.14/154.08 = 78.84/x
  3. Step 3: Cross multiply
    103.14x = 154.08 × 78.84
  4. Step 4: Simplify right side
    103.14x = 12,147.67
  5. Step 5: Solve for x
    x = 12,147.67/103.14
  6. Step 6: Final answer
    x = 117.78

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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.