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Finding the Fourth Proportional to 78.20, 116.77 and 69.54

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Solution

The fourth proportional to 78.20, 116.77 and 69.54 is: 103.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.20 : 116.77 = 69.54 : x
  2. Step 2: Convert to fraction form
    78.20/116.77 = 69.54/x
  3. Step 3: Cross multiply
    78.20x = 116.77 × 69.54
  4. Step 4: Simplify right side
    78.20x = 8,119.84
  5. Step 5: Solve for x
    x = 8,119.84/78.20
  6. Step 6: Final answer
    x = 103.83

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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.