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Finding the Fourth Proportional to 209.39, 288.77 and 143.78

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Solution

The fourth proportional to 209.39, 288.77 and 143.78 is: 198.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.39 : 288.77 = 143.78 : x
  2. Step 2: Convert to fraction form
    209.39/288.77 = 143.78/x
  3. Step 3: Cross multiply
    209.39x = 288.77 × 143.78
  4. Step 4: Simplify right side
    209.39x = 41,517.19
  5. Step 5: Solve for x
    x = 41,517.19/209.39
  6. Step 6: Final answer
    x = 198.28

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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.