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Finding the Fourth Proportional to 494, 681.78 and 287

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Solution

The fourth proportional to 494, 681.78 and 287 is: 396.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    494 : 681.78 = 287 : x
  2. Step 2: Convert to fraction form
    494/681.78 = 287/x
  3. Step 3: Cross multiply
    494x = 681.78 × 287
  4. Step 4: Simplify right side
    494x = 195,670.86
  5. Step 5: Solve for x
    x = 195,670.86/494
  6. Step 6: Final answer
    x = 396.09

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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.