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Finding the Fourth Proportional to 680.49, 939.14 and 400.81

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Solution

The fourth proportional to 680.49, 939.14 and 400.81 is: 553.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.49 : 939.14 = 400.81 : x
  2. Step 2: Convert to fraction form
    680.49/939.14 = 400.81/x
  3. Step 3: Cross multiply
    680.49x = 939.14 × 400.81
  4. Step 4: Simplify right side
    680.49x = 376,417.71
  5. Step 5: Solve for x
    x = 376,417.71/680.49
  6. Step 6: Final answer
    x = 553.16

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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.