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Finding the Fourth Proportional to 399.28, 599.12 and 206.80

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Solution

The fourth proportional to 399.28, 599.12 and 206.80 is: 310.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.28 : 599.12 = 206.80 : x
  2. Step 2: Convert to fraction form
    399.28/599.12 = 206.80/x
  3. Step 3: Cross multiply
    399.28x = 599.12 × 206.80
  4. Step 4: Simplify right side
    399.28x = 123,898.02
  5. Step 5: Solve for x
    x = 123,898.02/399.28
  6. Step 6: Final answer
    x = 310.30

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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.