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Finding the Fourth Proportional to 209.16, 288.62 and 121.82

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Solution

The fourth proportional to 209.16, 288.62 and 121.82 is: 168.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.16 : 288.62 = 121.82 : x
  2. Step 2: Convert to fraction form
    209.16/288.62 = 121.82/x
  3. Step 3: Cross multiply
    209.16x = 288.62 × 121.82
  4. Step 4: Simplify right side
    209.16x = 35,159.69
  5. Step 5: Solve for x
    x = 35,159.69/209.16
  6. Step 6: Final answer
    x = 168.10

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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.