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Finding the Fourth Proportional to 689.62, 951.44 and 394.78

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Solution

The fourth proportional to 689.62, 951.44 and 394.78 is: 544.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.62 : 951.44 = 394.78 : x
  2. Step 2: Convert to fraction form
    689.62/951.44 = 394.78/x
  3. Step 3: Cross multiply
    689.62x = 951.44 × 394.78
  4. Step 4: Simplify right side
    689.62x = 375,609.48
  5. Step 5: Solve for x
    x = 375,609.48/689.62
  6. Step 6: Final answer
    x = 544.66

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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.