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Finding the Fourth Proportional to 76.83, 105.96 and 57.15

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Solution

The fourth proportional to 76.83, 105.96 and 57.15 is: 78.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.83 : 105.96 = 57.15 : x
  2. Step 2: Convert to fraction form
    76.83/105.96 = 57.15/x
  3. Step 3: Cross multiply
    76.83x = 105.96 × 57.15
  4. Step 4: Simplify right side
    76.83x = 6,055.61
  5. Step 5: Solve for x
    x = 6,055.61/76.83
  6. Step 6: Final answer
    x = 78.82

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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.