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Finding the Fourth Proportional to 644.99, 890.09 and 396.15

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Solution

The fourth proportional to 644.99, 890.09 and 396.15 is: 546.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.99 : 890.09 = 396.15 : x
  2. Step 2: Convert to fraction form
    644.99/890.09 = 396.15/x
  3. Step 3: Cross multiply
    644.99x = 890.09 × 396.15
  4. Step 4: Simplify right side
    644.99x = 352,607.17
  5. Step 5: Solve for x
    x = 352,607.17/644.99
  6. Step 6: Final answer
    x = 546.69

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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.