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Finding the Fourth Proportional to 639.12, 881.19 and 551.64

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Solution

The fourth proportional to 639.12, 881.19 and 551.64 is: 760.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.12 : 881.19 = 551.64 : x
  2. Step 2: Convert to fraction form
    639.12/881.19 = 551.64/x
  3. Step 3: Cross multiply
    639.12x = 881.19 × 551.64
  4. Step 4: Simplify right side
    639.12x = 486,099.65
  5. Step 5: Solve for x
    x = 486,099.65/639.12
  6. Step 6: Final answer
    x = 760.58

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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.