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Finding the Fourth Proportional to 639.19, 882.17 and 390.54

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Solution

The fourth proportional to 639.19, 882.17 and 390.54 is: 539.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.19 : 882.17 = 390.54 : x
  2. Step 2: Convert to fraction form
    639.19/882.17 = 390.54/x
  3. Step 3: Cross multiply
    639.19x = 882.17 × 390.54
  4. Step 4: Simplify right side
    639.19x = 344,522.67
  5. Step 5: Solve for x
    x = 344,522.67/639.19
  6. Step 6: Final answer
    x = 539.00

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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.