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Finding the Fourth Proportional to 209.45, 288.83 and 138.42

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Solution

The fourth proportional to 209.45, 288.83 and 138.42 is: 190.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.45 : 288.83 = 138.42 : x
  2. Step 2: Convert to fraction form
    209.45/288.83 = 138.42/x
  3. Step 3: Cross multiply
    209.45x = 288.83 × 138.42
  4. Step 4: Simplify right side
    209.45x = 39,979.16
  5. Step 5: Solve for x
    x = 39,979.16/209.45
  6. Step 6: Final answer
    x = 190.88

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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.