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Finding the Fourth Proportional to 78.76, 107.90 and 76.02

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Solution

The fourth proportional to 78.76, 107.90 and 76.02 is: 104.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.76 : 107.90 = 76.02 : x
  2. Step 2: Convert to fraction form
    78.76/107.90 = 76.02/x
  3. Step 3: Cross multiply
    78.76x = 107.90 × 76.02
  4. Step 4: Simplify right side
    78.76x = 8,202.56
  5. Step 5: Solve for x
    x = 8,202.56/78.76
  6. Step 6: Final answer
    x = 104.15

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.