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Finding the Fourth Proportional to 399.20, 599.31 and 313.09

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Solution

The fourth proportional to 399.20, 599.31 and 313.09 is: 470.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.20 : 599.31 = 313.09 : x
  2. Step 2: Convert to fraction form
    399.20/599.31 = 313.09/x
  3. Step 3: Cross multiply
    399.20x = 599.31 × 313.09
  4. Step 4: Simplify right side
    399.20x = 187,636.47
  5. Step 5: Solve for x
    x = 187,636.47/399.20
  6. Step 6: Final answer
    x = 470.04

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.