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Finding the Fourth Proportional to 640.21, 883.42 and 378.18

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Solution

The fourth proportional to 640.21, 883.42 and 378.18 is: 521.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.21 : 883.42 = 378.18 : x
  2. Step 2: Convert to fraction form
    640.21/883.42 = 378.18/x
  3. Step 3: Cross multiply
    640.21x = 883.42 × 378.18
  4. Step 4: Simplify right side
    640.21x = 334,091.78
  5. Step 5: Solve for x
    x = 334,091.78/640.21
  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.