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Finding the Fourth Proportional to 781.56, 1,078.55 and 450.09

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Solution

The fourth proportional to 781.56, 1,078.55 and 450.09 is: 621.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.56 : 1,078.55 = 450.09 : x
  2. Step 2: Convert to fraction form
    781.56/1,078.55 = 450.09/x
  3. Step 3: Cross multiply
    781.56x = 1,078.55 × 450.09
  4. Step 4: Simplify right side
    781.56x = 485,442.32
  5. Step 5: Solve for x
    x = 485,442.32/781.56
  6. Step 6: Final answer
    x = 621.12

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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.