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Finding the Fourth Proportional to 645.09, 890.34 and 396.48

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Solution

The fourth proportional to 645.09, 890.34 and 396.48 is: 547.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.09 : 890.34 = 396.48 : x
  2. Step 2: Convert to fraction form
    645.09/890.34 = 396.48/x
  3. Step 3: Cross multiply
    645.09x = 890.34 × 396.48
  4. Step 4: Simplify right side
    645.09x = 353,002.00
  5. Step 5: Solve for x
    x = 353,002.00/645.09
  6. Step 6: Final answer
    x = 547.21

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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.