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Finding the Fourth Proportional to 809.94, 1,215.09 and 399.27

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Solution

The fourth proportional to 809.94, 1,215.09 and 399.27 is: 598.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.94 : 1,215.09 = 399.27 : x
  2. Step 2: Convert to fraction form
    809.94/1,215.09 = 399.27/x
  3. Step 3: Cross multiply
    809.94x = 1,215.09 × 399.27
  4. Step 4: Simplify right side
    809.94x = 485,148.98
  5. Step 5: Solve for x
    x = 485,148.98/809.94
  6. Step 6: Final answer
    x = 598.99

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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.