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Finding the Fourth Proportional to 639.66, 882.60 and 387.51

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Solution

The fourth proportional to 639.66, 882.60 and 387.51 is: 534.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.66 : 882.60 = 387.51 : x
  2. Step 2: Convert to fraction form
    639.66/882.60 = 387.51/x
  3. Step 3: Cross multiply
    639.66x = 882.60 × 387.51
  4. Step 4: Simplify right side
    639.66x = 342,016.33
  5. Step 5: Solve for x
    x = 342,016.33/639.66
  6. Step 6: Final answer
    x = 534.68

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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.