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Finding the Fourth Proportional to 645.35, 890.61 and 622.11

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Solution

The fourth proportional to 645.35, 890.61 and 622.11 is: 858.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.35 : 890.61 = 622.11 : x
  2. Step 2: Convert to fraction form
    645.35/890.61 = 622.11/x
  3. Step 3: Cross multiply
    645.35x = 890.61 × 622.11
  4. Step 4: Simplify right side
    645.35x = 554,057.39
  5. Step 5: Solve for x
    x = 554,057.39/645.35
  6. Step 6: Final answer
    x = 858.54

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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.