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Finding the Fourth Proportional to 76.78, 105.94 and 49.16

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Solution

The fourth proportional to 76.78, 105.94 and 49.16 is: 67.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.78 : 105.94 = 49.16 : x
  2. Step 2: Convert to fraction form
    76.78/105.94 = 49.16/x
  3. Step 3: Cross multiply
    76.78x = 105.94 × 49.16
  4. Step 4: Simplify right side
    76.78x = 5,208.01
  5. Step 5: Solve for x
    x = 5,208.01/76.78
  6. Step 6: Final answer
    x = 67.83

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.