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Finding the Fourth Proportional to 311.87, 430.49 and 187.56

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Solution

The fourth proportional to 311.87, 430.49 and 187.56 is: 258.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.87 : 430.49 = 187.56 : x
  2. Step 2: Convert to fraction form
    311.87/430.49 = 187.56/x
  3. Step 3: Cross multiply
    311.87x = 430.49 × 187.56
  4. Step 4: Simplify right side
    311.87x = 80,741.77
  5. Step 5: Solve for x
    x = 80,741.77/311.87
  6. Step 6: Final answer
    x = 258.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.