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Finding the Fourth Proportional to 645.30, 890.50 and 396.63

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Solution

The fourth proportional to 645.30, 890.50 and 396.63 is: 547.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.30 : 890.50 = 396.63 : x
  2. Step 2: Convert to fraction form
    645.30/890.50 = 396.63/x
  3. Step 3: Cross multiply
    645.30x = 890.50 × 396.63
  4. Step 4: Simplify right side
    645.30x = 353,199.02
  5. Step 5: Solve for x
    x = 353,199.02/645.30
  6. Step 6: Final answer
    x = 547.34

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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.