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Finding the Fourth Proportional to 639.05, 881.78 and 359.30

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Solution

The fourth proportional to 639.05, 881.78 and 359.30 is: 495.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.05 : 881.78 = 359.30 : x
  2. Step 2: Convert to fraction form
    639.05/881.78 = 359.30/x
  3. Step 3: Cross multiply
    639.05x = 881.78 × 359.30
  4. Step 4: Simplify right side
    639.05x = 316,817.35
  5. Step 5: Solve for x
    x = 316,817.35/639.05
  6. Step 6: Final answer
    x = 495.77

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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.