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Finding the Fourth Proportional to 639.38, 881.79 and 442.70

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Solution

The fourth proportional to 639.38, 881.79 and 442.70 is: 610.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.38 : 881.79 = 442.70 : x
  2. Step 2: Convert to fraction form
    639.38/881.79 = 442.70/x
  3. Step 3: Cross multiply
    639.38x = 881.79 × 442.70
  4. Step 4: Simplify right side
    639.38x = 390,368.43
  5. Step 5: Solve for x
    x = 390,368.43/639.38
  6. Step 6: Final answer
    x = 610.54

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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.