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Finding the Fourth Proportional to 640.20, 883.36 and 378.20

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Solution

The fourth proportional to 640.20, 883.36 and 378.20 is: 521.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.20 : 883.36 = 378.20 : x
  2. Step 2: Convert to fraction form
    640.20/883.36 = 378.20/x
  3. Step 3: Cross multiply
    640.20x = 883.36 × 378.20
  4. Step 4: Simplify right side
    640.20x = 334,086.75
  5. Step 5: Solve for x
    x = 334,086.75/640.20
  6. Step 6: Final answer
    x = 521.85

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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.