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Finding the Fourth Proportional to 680.91, 939.57 and 386.11

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Solution

The fourth proportional to 680.91, 939.57 and 386.11 is: 532.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.91 : 939.57 = 386.11 : x
  2. Step 2: Convert to fraction form
    680.91/939.57 = 386.11/x
  3. Step 3: Cross multiply
    680.91x = 939.57 × 386.11
  4. Step 4: Simplify right side
    680.91x = 362,772.67
  5. Step 5: Solve for x
    x = 362,772.67/680.91
  6. Step 6: Final answer
    x = 532.78

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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.