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Finding the Fourth Proportional to 209.61, 289.23 and 121.10

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Solution

The fourth proportional to 209.61, 289.23 and 121.10 is: 167.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.61 : 289.23 = 121.10 : x
  2. Step 2: Convert to fraction form
    209.61/289.23 = 121.10/x
  3. Step 3: Cross multiply
    209.61x = 289.23 × 121.10
  4. Step 4: Simplify right side
    209.61x = 35,024.31
  5. Step 5: Solve for x
    x = 35,024.31/209.61
  6. Step 6: Final answer
    x = 167.09

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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.