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Finding the Fourth Proportional to 680.69, 1,019.72 and 419.92

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Solution

The fourth proportional to 680.69, 1,019.72 and 419.92 is: 629.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.69 : 1,019.72 = 419.92 : x
  2. Step 2: Convert to fraction form
    680.69/1,019.72 = 419.92/x
  3. Step 3: Cross multiply
    680.69x = 1,019.72 × 419.92
  4. Step 4: Simplify right side
    680.69x = 428,193.62
  5. Step 5: Solve for x
    x = 428,193.62/680.69
  6. Step 6: Final answer
    x = 629.06

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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.