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Finding the Fourth Proportional to 209.05, 288.49 and 115.80

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Solution

The fourth proportional to 209.05, 288.49 and 115.80 is: 159.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.05 : 288.49 = 115.80 : x
  2. Step 2: Convert to fraction form
    209.05/288.49 = 115.80/x
  3. Step 3: Cross multiply
    209.05x = 288.49 × 115.80
  4. Step 4: Simplify right side
    209.05x = 33,405.12
  5. Step 5: Solve for x
    x = 33,405.12/209.05
  6. Step 6: Final answer
    x = 159.79

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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.