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Finding the Fourth Proportional to 638.34, 881.31 and 498.21

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Solution

The fourth proportional to 638.34, 881.31 and 498.21 is: 687.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.34 : 881.31 = 498.21 : x
  2. Step 2: Convert to fraction form
    638.34/881.31 = 498.21/x
  3. Step 3: Cross multiply
    638.34x = 881.31 × 498.21
  4. Step 4: Simplify right side
    638.34x = 439,077.46
  5. Step 5: Solve for x
    x = 439,077.46/638.34
  6. Step 6: Final answer
    x = 687.84

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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.