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Finding the Fourth Proportional to 421.38, 581.28 and 255.60

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Solution

The fourth proportional to 421.38, 581.28 and 255.60 is: 352.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.38 : 581.28 = 255.60 : x
  2. Step 2: Convert to fraction form
    421.38/581.28 = 255.60/x
  3. Step 3: Cross multiply
    421.38x = 581.28 × 255.60
  4. Step 4: Simplify right side
    421.38x = 148,575.17
  5. Step 5: Solve for x
    x = 148,575.17/421.38
  6. Step 6: Final answer
    x = 352.59

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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.