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Finding the Fourth Proportional to 209.95, 289.77 and 121.49

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Solution

The fourth proportional to 209.95, 289.77 and 121.49 is: 167.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.95 : 289.77 = 121.49 : x
  2. Step 2: Convert to fraction form
    209.95/289.77 = 121.49/x
  3. Step 3: Cross multiply
    209.95x = 289.77 × 121.49
  4. Step 4: Simplify right side
    209.95x = 35,204.25
  5. Step 5: Solve for x
    x = 35,204.25/209.95
  6. Step 6: Final answer
    x = 167.68

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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.