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Finding the Fourth Proportional to 311.75, 430.21 and 187.41

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Solution

The fourth proportional to 311.75, 430.21 and 187.41 is: 258.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.75 : 430.21 = 187.41 : x
  2. Step 2: Convert to fraction form
    311.75/430.21 = 187.41/x
  3. Step 3: Cross multiply
    311.75x = 430.21 × 187.41
  4. Step 4: Simplify right side
    311.75x = 80,627.50
  5. Step 5: Solve for x
    x = 80,627.50/311.75
  6. Step 6: Final answer
    x = 258.63

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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.