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Finding the Fourth Proportional to 679.69, 1,019.72 and 289.76

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Solution

The fourth proportional to 679.69, 1,019.72 and 289.76 is: 434.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.69 : 1,019.72 = 289.76 : x
  2. Step 2: Convert to fraction form
    679.69/1,019.72 = 289.76/x
  3. Step 3: Cross multiply
    679.69x = 1,019.72 × 289.76
  4. Step 4: Simplify right side
    679.69x = 295,469.69
  5. Step 5: Solve for x
    x = 295,469.69/679.69
  6. Step 6: Final answer
    x = 434.71

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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.