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Finding the Fourth Proportional to 389.91, 584.28 and 287.85

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Solution

The fourth proportional to 389.91, 584.28 and 287.85 is: 431.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.91 : 584.28 = 287.85 : x
  2. Step 2: Convert to fraction form
    389.91/584.28 = 287.85/x
  3. Step 3: Cross multiply
    389.91x = 584.28 × 287.85
  4. Step 4: Simplify right side
    389.91x = 168,185.00
  5. Step 5: Solve for x
    x = 168,185.00/389.91
  6. Step 6: Final answer
    x = 431.34

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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.