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Finding the Fourth Proportional to 311.98, 430.57 and 187.71

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Solution

The fourth proportional to 311.98, 430.57 and 187.71 is: 259.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.98 : 430.57 = 187.71 : x
  2. Step 2: Convert to fraction form
    311.98/430.57 = 187.71/x
  3. Step 3: Cross multiply
    311.98x = 430.57 × 187.71
  4. Step 4: Simplify right side
    311.98x = 80,820.61
  5. Step 5: Solve for x
    x = 80,820.61/311.98
  6. Step 6: Final answer
    x = 259.05

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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.