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Finding the Fourth Proportional to 639.98, 883.18 and 387.87

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Solution

The fourth proportional to 639.98, 883.18 and 387.87 is: 535.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.98 : 883.18 = 387.87 : x
  2. Step 2: Convert to fraction form
    639.98/883.18 = 387.87/x
  3. Step 3: Cross multiply
    639.98x = 883.18 × 387.87
  4. Step 4: Simplify right side
    639.98x = 342,559.03
  5. Step 5: Solve for x
    x = 342,559.03/639.98
  6. Step 6: Final answer
    x = 535.27

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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.