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Finding the Fourth Proportional to 387.21, 581.02 and 255.43

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Solution

The fourth proportional to 387.21, 581.02 and 255.43 is: 383.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.21 : 581.02 = 255.43 : x
  2. Step 2: Convert to fraction form
    387.21/581.02 = 255.43/x
  3. Step 3: Cross multiply
    387.21x = 581.02 × 255.43
  4. Step 4: Simplify right side
    387.21x = 148,409.94
  5. Step 5: Solve for x
    x = 148,409.94/387.21
  6. Step 6: Final answer
    x = 383.28

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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.