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Finding the Fourth Proportional to 674.50, 1,012.20 and 289.78

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Solution

The fourth proportional to 674.50, 1,012.20 and 289.78 is: 434.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    674.50 : 1,012.20 = 289.78 : x
  2. Step 2: Convert to fraction form
    674.50/1,012.20 = 289.78/x
  3. Step 3: Cross multiply
    674.50x = 1,012.20 × 289.78
  4. Step 4: Simplify right side
    674.50x = 293,315.32
  5. Step 5: Solve for x
    x = 293,315.32/674.50
  6. Step 6: Final answer
    x = 434.86

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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.