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Finding the Fourth Proportional to 391.87, 587.81 and 172.71

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Solution

The fourth proportional to 391.87, 587.81 and 172.71 is: 259.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.87 : 587.81 = 172.71 : x
  2. Step 2: Convert to fraction form
    391.87/587.81 = 172.71/x
  3. Step 3: Cross multiply
    391.87x = 587.81 × 172.71
  4. Step 4: Simplify right side
    391.87x = 101,520.67
  5. Step 5: Solve for x
    x = 101,520.67/391.87
  6. Step 6: Final answer
    x = 259.07

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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.