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Finding the Fourth Proportional to 209.08, 288.50 and 115.80

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Solution

The fourth proportional to 209.08, 288.50 and 115.80 is: 159.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.08 : 288.50 = 115.80 : x
  2. Step 2: Convert to fraction form
    209.08/288.50 = 115.80/x
  3. Step 3: Cross multiply
    209.08x = 288.50 × 115.80
  4. Step 4: Simplify right side
    209.08x = 33,406.64
  5. Step 5: Solve for x
    x = 33,406.64/209.08
  6. Step 6: Final answer
    x = 159.78

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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.