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Finding the Fourth Proportional to 486.38, 725.64 and 428.06

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Solution

The fourth proportional to 486.38, 725.64 and 428.06 is: 638.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    486.38 : 725.64 = 428.06 : x
  2. Step 2: Convert to fraction form
    486.38/725.64 = 428.06/x
  3. Step 3: Cross multiply
    486.38x = 725.64 × 428.06
  4. Step 4: Simplify right side
    486.38x = 310,617.46
  5. Step 5: Solve for x
    x = 310,617.46/486.38
  6. Step 6: Final answer
    x = 638.63

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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.