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Finding the Fourth Proportional to 420.90, 579.15 and 379.50

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Solution

The fourth proportional to 420.90, 579.15 and 379.50 is: 522.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.90 : 579.15 = 379.50 : x
  2. Step 2: Convert to fraction form
    420.90/579.15 = 379.50/x
  3. Step 3: Cross multiply
    420.90x = 579.15 × 379.50
  4. Step 4: Simplify right side
    420.90x = 219,787.43
  5. Step 5: Solve for x
    x = 219,787.43/420.90
  6. Step 6: Final answer
    x = 522.18

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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.