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Finding the Fourth Proportional to 311.78, 430.23 and 185.74

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Solution

The fourth proportional to 311.78, 430.23 and 185.74 is: 256.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.78 : 430.23 = 185.74 : x
  2. Step 2: Convert to fraction form
    311.78/430.23 = 185.74/x
  3. Step 3: Cross multiply
    311.78x = 430.23 × 185.74
  4. Step 4: Simplify right side
    311.78x = 79,910.92
  5. Step 5: Solve for x
    x = 79,910.92/311.78
  6. Step 6: Final answer
    x = 256.31

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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.