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Finding the Fourth Proportional to 639.40, 882.76 and 415.72

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Solution

The fourth proportional to 639.40, 882.76 and 415.72 is: 573.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.40 : 882.76 = 415.72 : x
  2. Step 2: Convert to fraction form
    639.40/882.76 = 415.72/x
  3. Step 3: Cross multiply
    639.40x = 882.76 × 415.72
  4. Step 4: Simplify right side
    639.40x = 366,980.99
  5. Step 5: Solve for x
    x = 366,980.99/639.40
  6. Step 6: Final answer
    x = 573.95

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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.