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Finding the Fourth Proportional to 76.97, 105.28 and 75.78

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Solution

The fourth proportional to 76.97, 105.28 and 75.78 is: 103.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.97 : 105.28 = 75.78 : x
  2. Step 2: Convert to fraction form
    76.97/105.28 = 75.78/x
  3. Step 3: Cross multiply
    76.97x = 105.28 × 75.78
  4. Step 4: Simplify right side
    76.97x = 7,978.12
  5. Step 5: Solve for x
    x = 7,978.12/76.97
  6. Step 6: Final answer
    x = 103.65

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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.