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Finding the Fourth Proportional to 644.79, 966.65 and 438.85

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Solution

The fourth proportional to 644.79, 966.65 and 438.85 is: 657.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.79 : 966.65 = 438.85 : x
  2. Step 2: Convert to fraction form
    644.79/966.65 = 438.85/x
  3. Step 3: Cross multiply
    644.79x = 966.65 × 438.85
  4. Step 4: Simplify right side
    644.79x = 424,209.74
  5. Step 5: Solve for x
    x = 424,209.74/644.79
  6. Step 6: Final answer
    x = 657.90

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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.