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Finding the Fourth Proportional to 668.81, 1,003.21 and 439.15

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Solution

The fourth proportional to 668.81, 1,003.21 and 439.15 is: 658.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.81 : 1,003.21 = 439.15 : x
  2. Step 2: Convert to fraction form
    668.81/1,003.21 = 439.15/x
  3. Step 3: Cross multiply
    668.81x = 1,003.21 × 439.15
  4. Step 4: Simplify right side
    668.81x = 440,559.67
  5. Step 5: Solve for x
    x = 440,559.67/668.81
  6. Step 6: Final answer
    x = 658.73

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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.