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Finding the Fourth Proportional to 617.21, 851.78 and 355.31

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Solution

The fourth proportional to 617.21, 851.78 and 355.31 is: 490.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    617.21 : 851.78 = 355.31 : x
  2. Step 2: Convert to fraction form
    617.21/851.78 = 355.31/x
  3. Step 3: Cross multiply
    617.21x = 851.78 × 355.31
  4. Step 4: Simplify right side
    617.21x = 302,645.95
  5. Step 5: Solve for x
    x = 302,645.95/617.21
  6. Step 6: Final answer
    x = 490.35

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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.