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Finding the Fourth Proportional to 561.38, 838.82 and 428.87

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Solution

The fourth proportional to 561.38, 838.82 and 428.87 is: 640.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.38 : 838.82 = 428.87 : x
  2. Step 2: Convert to fraction form
    561.38/838.82 = 428.87/x
  3. Step 3: Cross multiply
    561.38x = 838.82 × 428.87
  4. Step 4: Simplify right side
    561.38x = 359,738.39
  5. Step 5: Solve for x
    x = 359,738.39/561.38
  6. Step 6: Final answer
    x = 640.82

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.