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Finding the Fourth Proportional to 680.81, 939.34 and 401.05

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Solution

The fourth proportional to 680.81, 939.34 and 401.05 is: 553.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.81 : 939.34 = 401.05 : x
  2. Step 2: Convert to fraction form
    680.81/939.34 = 401.05/x
  3. Step 3: Cross multiply
    680.81x = 939.34 × 401.05
  4. Step 4: Simplify right side
    680.81x = 376,722.31
  5. Step 5: Solve for x
    x = 376,722.31/680.81
  6. Step 6: Final answer
    x = 553.34

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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.