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Finding the Fourth Proportional to 809.30, 1,212.60 and 397.55

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Solution

The fourth proportional to 809.30, 1,212.60 and 397.55 is: 595.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.30 : 1,212.60 = 397.55 : x
  2. Step 2: Convert to fraction form
    809.30/1,212.60 = 397.55/x
  3. Step 3: Cross multiply
    809.30x = 1,212.60 × 397.55
  4. Step 4: Simplify right side
    809.30x = 482,069.13
  5. Step 5: Solve for x
    x = 482,069.13/809.30
  6. Step 6: Final answer
    x = 595.66

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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.