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Finding the Fourth Proportional to 761.76, 1,142.49 and 213.78

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Solution

The fourth proportional to 761.76, 1,142.49 and 213.78 is: 320.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    761.76 : 1,142.49 = 213.78 : x
  2. Step 2: Convert to fraction form
    761.76/1,142.49 = 213.78/x
  3. Step 3: Cross multiply
    761.76x = 1,142.49 × 213.78
  4. Step 4: Simplify right side
    761.76x = 244,241.51
  5. Step 5: Solve for x
    x = 244,241.51/761.76
  6. Step 6: Final answer
    x = 320.63

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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.