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Finding the Fourth Proportional to 321.09, 443.21 and 203.15

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Solution

The fourth proportional to 321.09, 443.21 and 203.15 is: 280.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.09 : 443.21 = 203.15 : x
  2. Step 2: Convert to fraction form
    321.09/443.21 = 203.15/x
  3. Step 3: Cross multiply
    321.09x = 443.21 × 203.15
  4. Step 4: Simplify right side
    321.09x = 90,034.88
  5. Step 5: Solve for x
    x = 90,034.88/321.09
  6. Step 6: Final answer
    x = 280.40

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.