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Finding the Fourth Proportional to 689.45, 951.55 and 394.81

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Solution

The fourth proportional to 689.45, 951.55 and 394.81 is: 544.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.45 : 951.55 = 394.81 : x
  2. Step 2: Convert to fraction form
    689.45/951.55 = 394.81/x
  3. Step 3: Cross multiply
    689.45x = 951.55 × 394.81
  4. Step 4: Simplify right side
    689.45x = 375,678.09
  5. Step 5: Solve for x
    x = 375,678.09/689.45
  6. Step 6: Final answer
    x = 544.90

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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.