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Finding the Fourth Proportional to 681.15, 939.38 and 445

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Solution

The fourth proportional to 681.15, 939.38 and 445 is: 613.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.15 : 939.38 = 445 : x
  2. Step 2: Convert to fraction form
    681.15/939.38 = 445/x
  3. Step 3: Cross multiply
    681.15x = 939.38 × 445
  4. Step 4: Simplify right side
    681.15x = 418,025.21
  5. Step 5: Solve for x
    x = 418,025.21/681.15
  6. Step 6: Final answer
    x = 613.71

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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.