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Finding the Fourth Proportional to 640.69, 884.15 and 378.71

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Solution

The fourth proportional to 640.69, 884.15 and 378.71 is: 522.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.69 : 884.15 = 378.71 : x
  2. Step 2: Convert to fraction form
    640.69/884.15 = 378.71/x
  3. Step 3: Cross multiply
    640.69x = 884.15 × 378.71
  4. Step 4: Simplify right side
    640.69x = 334,832.97
  5. Step 5: Solve for x
    x = 334,832.97/640.69
  6. Step 6: Final answer
    x = 522.62

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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.