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Finding the Fourth Proportional to 427.66, 641.49 and 208.28

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Solution

The fourth proportional to 427.66, 641.49 and 208.28 is: 312.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.66 : 641.49 = 208.28 : x
  2. Step 2: Convert to fraction form
    427.66/641.49 = 208.28/x
  3. Step 3: Cross multiply
    427.66x = 641.49 × 208.28
  4. Step 4: Simplify right side
    427.66x = 133,608.30
  5. Step 5: Solve for x
    x = 133,608.30/427.66
  6. Step 6: Final answer
    x = 312.42

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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.