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Finding the Fourth Proportional to 681.78, 939.19 and 494.72

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Solution

The fourth proportional to 681.78, 939.19 and 494.72 is: 681.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.78 : 939.19 = 494.72 : x
  2. Step 2: Convert to fraction form
    681.78/939.19 = 494.72/x
  3. Step 3: Cross multiply
    681.78x = 939.19 × 494.72
  4. Step 4: Simplify right side
    681.78x = 464,636.08
  5. Step 5: Solve for x
    x = 464,636.08/681.78
  6. Step 6: Final answer
    x = 681.50

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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.