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Finding the Fourth Proportional to 355.78, 490.92 and 208.39

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Solution

The fourth proportional to 355.78, 490.92 and 208.39 is: 287.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.78 : 490.92 = 208.39 : x
  2. Step 2: Convert to fraction form
    355.78/490.92 = 208.39/x
  3. Step 3: Cross multiply
    355.78x = 490.92 × 208.39
  4. Step 4: Simplify right side
    355.78x = 102,302.82
  5. Step 5: Solve for x
    x = 102,302.82/355.78
  6. Step 6: Final answer
    x = 287.55

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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.