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Finding the Fourth Proportional to 661.38, 990.45 and 499.38

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Solution

The fourth proportional to 661.38, 990.45 and 499.38 is: 747.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.38 : 990.45 = 499.38 : x
  2. Step 2: Convert to fraction form
    661.38/990.45 = 499.38/x
  3. Step 3: Cross multiply
    661.38x = 990.45 × 499.38
  4. Step 4: Simplify right side
    661.38x = 494,610.92
  5. Step 5: Solve for x
    x = 494,610.92/661.38
  6. Step 6: Final answer
    x = 747.85

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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.