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Finding the Fourth Proportional to 639.52, 881.91 and 387.39

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Solution

The fourth proportional to 639.52, 881.91 and 387.39 is: 534.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.52 : 881.91 = 387.39 : x
  2. Step 2: Convert to fraction form
    639.52/881.91 = 387.39/x
  3. Step 3: Cross multiply
    639.52x = 881.91 × 387.39
  4. Step 4: Simplify right side
    639.52x = 341,643.11
  5. Step 5: Solve for x
    x = 341,643.11/639.52
  6. Step 6: Final answer
    x = 534.22

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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.