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Finding the Fourth Proportional to 638.02, 879.99 and 428.43

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Solution

The fourth proportional to 638.02, 879.99 and 428.43 is: 590.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.02 : 879.99 = 428.43 : x
  2. Step 2: Convert to fraction form
    638.02/879.99 = 428.43/x
  3. Step 3: Cross multiply
    638.02x = 879.99 × 428.43
  4. Step 4: Simplify right side
    638.02x = 377,014.12
  5. Step 5: Solve for x
    x = 377,014.12/638.02
  6. Step 6: Final answer
    x = 590.91

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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.