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Finding the Fourth Proportional to 669.85, 1,003.49 and 409.07

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Solution

The fourth proportional to 669.85, 1,003.49 and 409.07 is: 612.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    669.85 : 1,003.49 = 409.07 : x
  2. Step 2: Convert to fraction form
    669.85/1,003.49 = 409.07/x
  3. Step 3: Cross multiply
    669.85x = 1,003.49 × 409.07
  4. Step 4: Simplify right side
    669.85x = 410,491.65
  5. Step 5: Solve for x
    x = 410,491.65/669.85
  6. Step 6: Final answer
    x = 612.81

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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.