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Finding the Fourth Proportional to 421.11, 581.09 and 281.39

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Solution

The fourth proportional to 421.11, 581.09 and 281.39 is: 388.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.11 : 581.09 = 281.39 : x
  2. Step 2: Convert to fraction form
    421.11/581.09 = 281.39/x
  3. Step 3: Cross multiply
    421.11x = 581.09 × 281.39
  4. Step 4: Simplify right side
    421.11x = 163,508.60
  5. Step 5: Solve for x
    x = 163,508.60/421.11
  6. Step 6: Final answer
    x = 388.28

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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.