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Finding the Fourth Proportional to 561.20, 769.50 and 505.71

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Solution

The fourth proportional to 561.20, 769.50 and 505.71 is: 693.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.20 : 769.50 = 505.71 : x
  2. Step 2: Convert to fraction form
    561.20/769.50 = 505.71/x
  3. Step 3: Cross multiply
    561.20x = 769.50 × 505.71
  4. Step 4: Simplify right side
    561.20x = 389,143.85
  5. Step 5: Solve for x
    x = 389,143.85/561.20
  6. Step 6: Final answer
    x = 693.42

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.