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Finding the Fourth Proportional to 621.11, 856.87 and 355.50

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Solution

The fourth proportional to 621.11, 856.87 and 355.50 is: 490.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.11 : 856.87 = 355.50 : x
  2. Step 2: Convert to fraction form
    621.11/856.87 = 355.50/x
  3. Step 3: Cross multiply
    621.11x = 856.87 × 355.50
  4. Step 4: Simplify right side
    621.11x = 304,616.40
  5. Step 5: Solve for x
    x = 304,616.40/621.11
  6. Step 6: Final answer
    x = 490.44

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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.