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Finding the Fourth Proportional to 356.38, 491.78 and 209

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Solution

The fourth proportional to 356.38, 491.78 and 209 is: 288.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    356.38 : 491.78 = 209 : x
  2. Step 2: Convert to fraction form
    356.38/491.78 = 209/x
  3. Step 3: Cross multiply
    356.38x = 491.78 × 209
  4. Step 4: Simplify right side
    356.38x = 102,780.98
  5. Step 5: Solve for x
    x = 102,780.98/356.38
  6. Step 6: Final answer
    x = 288.41

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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.