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Finding the Fourth Proportional to 609.42, 839.79 and 399.36

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Solution

The fourth proportional to 609.42, 839.79 and 399.36 is: 550.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    609.42 : 839.79 = 399.36 : x
  2. Step 2: Convert to fraction form
    609.42/839.79 = 399.36/x
  3. Step 3: Cross multiply
    609.42x = 839.79 × 399.36
  4. Step 4: Simplify right side
    609.42x = 335,378.53
  5. Step 5: Solve for x
    x = 335,378.53/609.42
  6. Step 6: Final answer
    x = 550.32

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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.