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Finding the Fourth Proportional to 356.39, 491.78 and 209.07

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Solution

The fourth proportional to 356.39, 491.78 and 209.07 is: 288.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    356.39 : 491.78 = 209.07 : x
  2. Step 2: Convert to fraction form
    356.39/491.78 = 209.07/x
  3. Step 3: Cross multiply
    356.39x = 491.78 × 209.07
  4. Step 4: Simplify right side
    356.39x = 102,816.44
  5. Step 5: Solve for x
    x = 102,816.44/356.39
  6. Step 6: Final answer
    x = 288.49

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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.