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Finding the Fourth Proportional to 621.56, 857.58 and 490.16

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Solution

The fourth proportional to 621.56, 857.58 and 490.16 is: 676.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.56 : 857.58 = 490.16 : x
  2. Step 2: Convert to fraction form
    621.56/857.58 = 490.16/x
  3. Step 3: Cross multiply
    621.56x = 857.58 × 490.16
  4. Step 4: Simplify right side
    621.56x = 420,351.41
  5. Step 5: Solve for x
    x = 420,351.41/621.56
  6. Step 6: Final answer
    x = 676.28

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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.