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Finding the Fourth Proportional to 391.99, 587.99 and 145.14

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Solution

The fourth proportional to 391.99, 587.99 and 145.14 is: 217.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.99 : 587.99 = 145.14 : x
  2. Step 2: Convert to fraction form
    391.99/587.99 = 145.14/x
  3. Step 3: Cross multiply
    391.99x = 587.99 × 145.14
  4. Step 4: Simplify right side
    391.99x = 85,340.87
  5. Step 5: Solve for x
    x = 85,340.87/391.99
  6. Step 6: Final answer
    x = 217.71

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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.