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Finding the Fourth Proportional to 311.70, 430.03 and 187.31

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Solution

The fourth proportional to 311.70, 430.03 and 187.31 is: 258.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.70 : 430.03 = 187.31 : x
  2. Step 2: Convert to fraction form
    311.70/430.03 = 187.31/x
  3. Step 3: Cross multiply
    311.70x = 430.03 × 187.31
  4. Step 4: Simplify right side
    311.70x = 80,550.76
  5. Step 5: Solve for x
    x = 80,550.76/311.70
  6. Step 6: Final answer
    x = 258.43

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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.