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Finding the Fourth Proportional to 638.86, 881.39 and 402.74

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Solution

The fourth proportional to 638.86, 881.39 and 402.74 is: 555.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.86 : 881.39 = 402.74 : x
  2. Step 2: Convert to fraction form
    638.86/881.39 = 402.74/x
  3. Step 3: Cross multiply
    638.86x = 881.39 × 402.74
  4. Step 4: Simplify right side
    638.86x = 354,968.99
  5. Step 5: Solve for x
    x = 354,968.99/638.86
  6. Step 6: Final answer
    x = 555.63

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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.