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Finding the Fourth Proportional to 644.15, 961.91 and 505.64

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Solution

The fourth proportional to 644.15, 961.91 and 505.64 is: 755.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.15 : 961.91 = 505.64 : x
  2. Step 2: Convert to fraction form
    644.15/961.91 = 505.64/x
  3. Step 3: Cross multiply
    644.15x = 961.91 × 505.64
  4. Step 4: Simplify right side
    644.15x = 486,380.17
  5. Step 5: Solve for x
    x = 486,380.17/644.15
  6. Step 6: Final answer
    x = 755.07

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.