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Finding the Fourth Proportional to 355.30, 490.31 and 217.30

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Solution

The fourth proportional to 355.30, 490.31 and 217.30 is: 299.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    355.30 : 490.31 = 217.30 : x
  2. Step 2: Convert to fraction form
    355.30/490.31 = 217.30/x
  3. Step 3: Cross multiply
    355.30x = 490.31 × 217.30
  4. Step 4: Simplify right side
    355.30x = 106,544.36
  5. Step 5: Solve for x
    x = 106,544.36/355.30
  6. Step 6: Final answer
    x = 299.87

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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.