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Finding the Fourth Proportional to 379.76, 570.90 and 311.79

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Solution

The fourth proportional to 379.76, 570.90 and 311.79 is: 468.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    379.76 : 570.90 = 311.79 : x
  2. Step 2: Convert to fraction form
    379.76/570.90 = 311.79/x
  3. Step 3: Cross multiply
    379.76x = 570.90 × 311.79
  4. Step 4: Simplify right side
    379.76x = 178,000.91
  5. Step 5: Solve for x
    x = 178,000.91/379.76
  6. Step 6: Final answer
    x = 468.72

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.