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Finding the Fourth Proportional to 620.76, 856.27 and 399.43

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Solution

The fourth proportional to 620.76, 856.27 and 399.43 is: 550.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.76 : 856.27 = 399.43 : x
  2. Step 2: Convert to fraction form
    620.76/856.27 = 399.43/x
  3. Step 3: Cross multiply
    620.76x = 856.27 × 399.43
  4. Step 4: Simplify right side
    620.76x = 342,021.50
  5. Step 5: Solve for x
    x = 342,021.50/620.76
  6. Step 6: Final answer
    x = 550.97

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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.