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Finding the Fourth Proportional to 397.40, 548.40 and 285.38

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Solution

The fourth proportional to 397.40, 548.40 and 285.38 is: 393.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    397.40 : 548.40 = 285.38 : x
  2. Step 2: Convert to fraction form
    397.40/548.40 = 285.38/x
  3. Step 3: Cross multiply
    397.40x = 548.40 × 285.38
  4. Step 4: Simplify right side
    397.40x = 156,502.39
  5. Step 5: Solve for x
    x = 156,502.39/397.40
  6. Step 6: Final answer
    x = 393.82

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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.