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Finding the Fourth Proportional to 421.21, 581.33 and 255.43

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Solution

The fourth proportional to 421.21, 581.33 and 255.43 is: 352.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.21 : 581.33 = 255.43 : x
  2. Step 2: Convert to fraction form
    421.21/581.33 = 255.43/x
  3. Step 3: Cross multiply
    421.21x = 581.33 × 255.43
  4. Step 4: Simplify right side
    421.21x = 148,489.12
  5. Step 5: Solve for x
    x = 148,489.12/421.21
  6. Step 6: Final answer
    x = 352.53

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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.