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Finding the Fourth Proportional to 213.70, 320.57 and 76.76

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Solution

The fourth proportional to 213.70, 320.57 and 76.76 is: 115.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.70 : 320.57 = 76.76 : x
  2. Step 2: Convert to fraction form
    213.70/320.57 = 76.76/x
  3. Step 3: Cross multiply
    213.70x = 320.57 × 76.76
  4. Step 4: Simplify right side
    213.70x = 24,604.97
  5. Step 5: Solve for x
    x = 24,604.97/213.70
  6. Step 6: Final answer
    x = 115.14

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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.