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Finding the Fourth Proportional to 680.81, 939.60 and 400.95

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Solution

The fourth proportional to 680.81, 939.60 and 400.95 is: 553.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.81 : 939.60 = 400.95 : x
  2. Step 2: Convert to fraction form
    680.81/939.60 = 400.95/x
  3. Step 3: Cross multiply
    680.81x = 939.60 × 400.95
  4. Step 4: Simplify right side
    680.81x = 376,732.62
  5. Step 5: Solve for x
    x = 376,732.62/680.81
  6. Step 6: Final answer
    x = 553.36

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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.