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Finding the Fourth Proportional to 608.81, 840.42 and 398.99

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Solution

The fourth proportional to 608.81, 840.42 and 398.99 is: 550.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    608.81 : 840.42 = 398.99 : x
  2. Step 2: Convert to fraction form
    608.81/840.42 = 398.99/x
  3. Step 3: Cross multiply
    608.81x = 840.42 × 398.99
  4. Step 4: Simplify right side
    608.81x = 335,314.97
  5. Step 5: Solve for x
    x = 335,314.97/608.81
  6. Step 6: Final answer
    x = 550.78

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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.