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Finding the Fourth Proportional to 644.63, 965.39 and 412.80

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Solution

The fourth proportional to 644.63, 965.39 and 412.80 is: 618.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.63 : 965.39 = 412.80 : x
  2. Step 2: Convert to fraction form
    644.63/965.39 = 412.80/x
  3. Step 3: Cross multiply
    644.63x = 965.39 × 412.80
  4. Step 4: Simplify right side
    644.63x = 398,507.31
  5. Step 5: Solve for x
    x = 398,507.31/644.63
  6. Step 6: Final answer
    x = 618.20

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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.