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Finding the Fourth Proportional to 421.20, 579.96 and 397.17

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Solution

The fourth proportional to 421.20, 579.96 and 397.17 is: 546.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.20 : 579.96 = 397.17 : x
  2. Step 2: Convert to fraction form
    421.20/579.96 = 397.17/x
  3. Step 3: Cross multiply
    421.20x = 579.96 × 397.17
  4. Step 4: Simplify right side
    421.20x = 230,342.71
  5. Step 5: Solve for x
    x = 230,342.71/421.20
  6. Step 6: Final answer
    x = 546.87

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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.