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Finding the Fourth Proportional to 644.30, 965.79 and 278.78

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Solution

The fourth proportional to 644.30, 965.79 and 278.78 is: 417.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.30 : 965.79 = 278.78 : x
  2. Step 2: Convert to fraction form
    644.30/965.79 = 278.78/x
  3. Step 3: Cross multiply
    644.30x = 965.79 × 278.78
  4. Step 4: Simplify right side
    644.30x = 269,242.94
  5. Step 5: Solve for x
    x = 269,242.94/644.30
  6. Step 6: Final answer
    x = 417.88

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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.