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Finding the Fourth Proportional to 761.57, 1,142.39 and 213.79

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Solution

The fourth proportional to 761.57, 1,142.39 and 213.79 is: 320.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    761.57 : 1,142.39 = 213.79 : x
  2. Step 2: Convert to fraction form
    761.57/1,142.39 = 213.79/x
  3. Step 3: Cross multiply
    761.57x = 1,142.39 × 213.79
  4. Step 4: Simplify right side
    761.57x = 244,230.18
  5. Step 5: Solve for x
    x = 244,230.18/761.57
  6. Step 6: Final answer
    x = 320.69

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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.