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Finding the Fourth Proportional to 621.88, 856.78 and 490.84

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Solution

The fourth proportional to 621.88, 856.78 and 490.84 is: 676.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.88 : 856.78 = 490.84 : x
  2. Step 2: Convert to fraction form
    621.88/856.78 = 490.84/x
  3. Step 3: Cross multiply
    621.88x = 856.78 × 490.84
  4. Step 4: Simplify right side
    621.88x = 420,541.90
  5. Step 5: Solve for x
    x = 420,541.90/621.88
  6. Step 6: Final answer
    x = 676.24

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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.