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Finding the Fourth Proportional to 645.22, 890.15 and 505.09

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Solution

The fourth proportional to 645.22, 890.15 and 505.09 is: 696.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.22 : 890.15 = 505.09 : x
  2. Step 2: Convert to fraction form
    645.22/890.15 = 505.09/x
  3. Step 3: Cross multiply
    645.22x = 890.15 × 505.09
  4. Step 4: Simplify right side
    645.22x = 449,605.86
  5. Step 5: Solve for x
    x = 449,605.86/645.22
  6. Step 6: Final answer
    x = 696.83

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.