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Finding the Fourth Proportional to 781.34, 1,078.23 and 449.82

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Solution

The fourth proportional to 781.34, 1,078.23 and 449.82 is: 620.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.34 : 1,078.23 = 449.82 : x
  2. Step 2: Convert to fraction form
    781.34/1,078.23 = 449.82/x
  3. Step 3: Cross multiply
    781.34x = 1,078.23 × 449.82
  4. Step 4: Simplify right side
    781.34x = 485,009.42
  5. Step 5: Solve for x
    x = 485,009.42/781.34
  6. Step 6: Final answer
    x = 620.74

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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.