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Finding the Fourth Proportional to 620.76, 856.48 and 399.99

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Solution

The fourth proportional to 620.76, 856.48 and 399.99 is: 551.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.76 : 856.48 = 399.99 : x
  2. Step 2: Convert to fraction form
    620.76/856.48 = 399.99/x
  3. Step 3: Cross multiply
    620.76x = 856.48 × 399.99
  4. Step 4: Simplify right side
    620.76x = 342,584.58
  5. Step 5: Solve for x
    x = 342,584.58/620.76
  6. Step 6: Final answer
    x = 551.88

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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.