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Finding the Fourth Proportional to 209.87, 289.59 and 121.33

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Solution

The fourth proportional to 209.87, 289.59 and 121.33 is: 167.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.87 : 289.59 = 121.33 : x
  2. Step 2: Convert to fraction form
    209.87/289.59 = 121.33/x
  3. Step 3: Cross multiply
    209.87x = 289.59 × 121.33
  4. Step 4: Simplify right side
    209.87x = 35,137.51
  5. Step 5: Solve for x
    x = 35,137.51/209.87
  6. Step 6: Final answer
    x = 167.43

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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.