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Finding the Fourth Proportional to 644.64, 965.34 and 427.56

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Solution

The fourth proportional to 644.64, 965.34 and 427.56 is: 640.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.64 : 965.34 = 427.56 : x
  2. Step 2: Convert to fraction form
    644.64/965.34 = 427.56/x
  3. Step 3: Cross multiply
    644.64x = 965.34 × 427.56
  4. Step 4: Simplify right side
    644.64x = 412,740.77
  5. Step 5: Solve for x
    x = 412,740.77/644.64
  6. Step 6: Final answer
    x = 640.27

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.