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Finding the Fourth Proportional to 76.68, 115 and 28.56

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Solution

The fourth proportional to 76.68, 115 and 28.56 is: 42.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.68 : 115 = 28.56 : x
  2. Step 2: Convert to fraction form
    76.68/115 = 28.56/x
  3. Step 3: Cross multiply
    76.68x = 115 × 28.56
  4. Step 4: Simplify right side
    76.68x = 3,284.40
  5. Step 5: Solve for x
    x = 3,284.40/76.68
  6. Step 6: Final answer
    x = 42.83

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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.