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Finding the Fourth Proportional to 638.40, 881.30 and 402.46

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Solution

The fourth proportional to 638.40, 881.30 and 402.46 is: 555.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.40 : 881.30 = 402.46 : x
  2. Step 2: Convert to fraction form
    638.40/881.30 = 402.46/x
  3. Step 3: Cross multiply
    638.40x = 881.30 × 402.46
  4. Step 4: Simplify right side
    638.40x = 354,687.02
  5. Step 5: Solve for x
    x = 354,687.02/638.40
  6. Step 6: Final answer
    x = 555.59

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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.