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Finding the Fourth Proportional to 644.51, 889.43 and 349.78

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Solution

The fourth proportional to 644.51, 889.43 and 349.78 is: 482.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    644.51 : 889.43 = 349.78 : x
  2. Step 2: Convert to fraction form
    644.51/889.43 = 349.78/x
  3. Step 3: Cross multiply
    644.51x = 889.43 × 349.78
  4. Step 4: Simplify right side
    644.51x = 311,100.85
  5. Step 5: Solve for x
    x = 311,100.85/644.51
  6. Step 6: Final answer
    x = 482.69

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.