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Finding the Fourth Proportional to 422.40, 579.18 and 380.79

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Solution

The fourth proportional to 422.40, 579.18 and 380.79 is: 522.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    422.40 : 579.18 = 380.79 : x
  2. Step 2: Convert to fraction form
    422.40/579.18 = 380.79/x
  3. Step 3: Cross multiply
    422.40x = 579.18 × 380.79
  4. Step 4: Simplify right side
    422.40x = 220,545.95
  5. Step 5: Solve for x
    x = 220,545.95/422.40
  6. Step 6: Final answer
    x = 522.13

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.