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Finding the Fourth Proportional to 639, 882.16 and 442.20

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Solution

The fourth proportional to 639, 882.16 and 442.20 is: 610.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    639 : 882.16 = 442.20 : x
  2. Step 2: Convert to fraction form
    639/882.16 = 442.20/x
  3. Step 3: Cross multiply
    639x = 882.16 × 442.20
  4. Step 4: Simplify right side
    639x = 390,091.15
  5. Step 5: Solve for x
    x = 390,091.15/639
  6. Step 6: Final answer
    x = 610.47

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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.