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Finding the Fourth Proportional to 421.56, 579.79 and 338.54

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Solution

The fourth proportional to 421.56, 579.79 and 338.54 is: 465.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.56 : 579.79 = 338.54 : x
  2. Step 2: Convert to fraction form
    421.56/579.79 = 338.54/x
  3. Step 3: Cross multiply
    421.56x = 579.79 × 338.54
  4. Step 4: Simplify right side
    421.56x = 196,282.11
  5. Step 5: Solve for x
    x = 196,282.11/421.56
  6. Step 6: Final answer
    x = 465.61

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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.