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Finding the Fourth Proportional to 681.29, 939.89 and 445.15

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Solution

The fourth proportional to 681.29, 939.89 and 445.15 is: 614.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.29 : 939.89 = 445.15 : x
  2. Step 2: Convert to fraction form
    681.29/939.89 = 445.15/x
  3. Step 3: Cross multiply
    681.29x = 939.89 × 445.15
  4. Step 4: Simplify right side
    681.29x = 418,394.32
  5. Step 5: Solve for x
    x = 418,394.32/681.29
  6. Step 6: Final answer
    x = 614.12

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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.