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Finding the Fourth Proportional to 809.22, 1,213.90 and 261.48

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Solution

The fourth proportional to 809.22, 1,213.90 and 261.48 is: 392.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.22 : 1,213.90 = 261.48 : x
  2. Step 2: Convert to fraction form
    809.22/1,213.90 = 261.48/x
  3. Step 3: Cross multiply
    809.22x = 1,213.90 × 261.48
  4. Step 4: Simplify right side
    809.22x = 317,410.57
  5. Step 5: Solve for x
    x = 317,410.57/809.22
  6. Step 6: Final answer
    x = 392.24

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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.