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Finding the Fourth Proportional to 76.75, 115.13 and 19.75

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Solution

The fourth proportional to 76.75, 115.13 and 19.75 is: 29.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.75 : 115.13 = 19.75 : x
  2. Step 2: Convert to fraction form
    76.75/115.13 = 19.75/x
  3. Step 3: Cross multiply
    76.75x = 115.13 × 19.75
  4. Step 4: Simplify right side
    76.75x = 2,273.82
  5. Step 5: Solve for x
    x = 2,273.82/76.75
  6. Step 6: Final answer
    x = 29.63

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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.