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Finding the Fourth Proportional to 809.28, 1,213.58 and 398.61

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Solution

The fourth proportional to 809.28, 1,213.58 and 398.61 is: 597.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.28 : 1,213.58 = 398.61 : x
  2. Step 2: Convert to fraction form
    809.28/1,213.58 = 398.61/x
  3. Step 3: Cross multiply
    809.28x = 1,213.58 × 398.61
  4. Step 4: Simplify right side
    809.28x = 483,746.12
  5. Step 5: Solve for x
    x = 483,746.12/809.28
  6. Step 6: Final answer
    x = 597.75

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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.