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Finding the Fourth Proportional to 389.25, 584.13 and 145.78

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Solution

The fourth proportional to 389.25, 584.13 and 145.78 is: 218.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.25 : 584.13 = 145.78 : x
  2. Step 2: Convert to fraction form
    389.25/584.13 = 145.78/x
  3. Step 3: Cross multiply
    389.25x = 584.13 × 145.78
  4. Step 4: Simplify right side
    389.25x = 85,153.56
  5. Step 5: Solve for x
    x = 85,153.56/389.25
  6. Step 6: Final answer
    x = 218.76

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.