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Finding the Fourth Proportional to 355.57, 490.71 and 208.21

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Solution

The fourth proportional to 355.57, 490.71 and 208.21 is: 287.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.57 : 490.71 = 208.21 : x
  2. Step 2: Convert to fraction form
    355.57/490.71 = 208.21/x
  3. Step 3: Cross multiply
    355.57x = 490.71 × 208.21
  4. Step 4: Simplify right side
    355.57x = 102,170.73
  5. Step 5: Solve for x
    x = 102,170.73/355.57
  6. Step 6: Final answer
    x = 287.34

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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.