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Finding the Fourth Proportional to 639.39, 881.78 and 418.26

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Solution

The fourth proportional to 639.39, 881.78 and 418.26 is: 576.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.39 : 881.78 = 418.26 : x
  2. Step 2: Convert to fraction form
    639.39/881.78 = 418.26/x
  3. Step 3: Cross multiply
    639.39x = 881.78 × 418.26
  4. Step 4: Simplify right side
    639.39x = 368,811.21
  5. Step 5: Solve for x
    x = 368,811.21/639.39
  6. Step 6: Final answer
    x = 576.82

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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.