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Finding the Fourth Proportional to 809.29, 1,213.68 and 261.38

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Solution

The fourth proportional to 809.29, 1,213.68 and 261.38 is: 391.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.29 : 1,213.68 = 261.38 : x
  2. Step 2: Convert to fraction form
    809.29/1,213.68 = 261.38/x
  3. Step 3: Cross multiply
    809.29x = 1,213.68 × 261.38
  4. Step 4: Simplify right side
    809.29x = 317,228.87
  5. Step 5: Solve for x
    x = 317,228.87/809.29
  6. Step 6: Final answer
    x = 391.98

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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.