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Finding the Fourth Proportional to 639.53, 958.64 and 408.58

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Solution

The fourth proportional to 639.53, 958.64 and 408.58 is: 612.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.53 : 958.64 = 408.58 : x
  2. Step 2: Convert to fraction form
    639.53/958.64 = 408.58/x
  3. Step 3: Cross multiply
    639.53x = 958.64 × 408.58
  4. Step 4: Simplify right side
    639.53x = 391,680.74
  5. Step 5: Solve for x
    x = 391,680.74/639.53
  6. Step 6: Final answer
    x = 612.45

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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.