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Finding the Fourth Proportional to 645.62, 891.57 and 644.30

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Solution

The fourth proportional to 645.62, 891.57 and 644.30 is: 889.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.62 : 891.57 = 644.30 : x
  2. Step 2: Convert to fraction form
    645.62/891.57 = 644.30/x
  3. Step 3: Cross multiply
    645.62x = 891.57 × 644.30
  4. Step 4: Simplify right side
    645.62x = 574,438.55
  5. Step 5: Solve for x
    x = 574,438.55/645.62
  6. Step 6: Final answer
    x = 889.75

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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.