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Finding the Fourth Proportional to 389.61, 584.42 and 115.72

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Solution

The fourth proportional to 389.61, 584.42 and 115.72 is: 173.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.61 : 584.42 = 115.72 : x
  2. Step 2: Convert to fraction form
    389.61/584.42 = 115.72/x
  3. Step 3: Cross multiply
    389.61x = 584.42 × 115.72
  4. Step 4: Simplify right side
    389.61x = 67,629.66
  5. Step 5: Solve for x
    x = 67,629.66/389.61
  6. Step 6: Final answer
    x = 173.58

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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.