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Finding the Fourth Proportional to 639.78, 960.06 and 429.18

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Solution

The fourth proportional to 639.78, 960.06 and 429.18 is: 644.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.78 : 960.06 = 429.18 : x
  2. Step 2: Convert to fraction form
    639.78/960.06 = 429.18/x
  3. Step 3: Cross multiply
    639.78x = 960.06 × 429.18
  4. Step 4: Simplify right side
    639.78x = 412,038.55
  5. Step 5: Solve for x
    x = 412,038.55/639.78
  6. Step 6: Final answer
    x = 644.03

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.