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Finding the Fourth Proportional to 644.37, 966.90 and 319.74

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Solution

The fourth proportional to 644.37, 966.90 and 319.74 is: 479.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.37 : 966.90 = 319.74 : x
  2. Step 2: Convert to fraction form
    644.37/966.90 = 319.74/x
  3. Step 3: Cross multiply
    644.37x = 966.90 × 319.74
  4. Step 4: Simplify right side
    644.37x = 309,156.61
  5. Step 5: Solve for x
    x = 309,156.61/644.37
  6. Step 6: Final answer
    x = 479.78

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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.