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Finding the Fourth Proportional to 644.22, 965.13 and 438.78

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Solution

The fourth proportional to 644.22, 965.13 and 438.78 is: 657.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.22 : 965.13 = 438.78 : x
  2. Step 2: Convert to fraction form
    644.22/965.13 = 438.78/x
  3. Step 3: Cross multiply
    644.22x = 965.13 × 438.78
  4. Step 4: Simplify right side
    644.22x = 423,479.74
  5. Step 5: Solve for x
    x = 423,479.74/644.22
  6. Step 6: Final answer
    x = 657.35

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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.