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Finding the Fourth Proportional to 761.78, 1,142.58 and 299.90

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Solution

The fourth proportional to 761.78, 1,142.58 and 299.90 is: 449.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    761.78 : 1,142.58 = 299.90 : x
  2. Step 2: Convert to fraction form
    761.78/1,142.58 = 299.90/x
  3. Step 3: Cross multiply
    761.78x = 1,142.58 × 299.90
  4. Step 4: Simplify right side
    761.78x = 342,659.74
  5. Step 5: Solve for x
    x = 342,659.74/761.78
  6. Step 6: Final answer
    x = 449.81

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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.