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Finding the Fourth Proportional to 213.38, 319.61 and 121.80

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Solution

The fourth proportional to 213.38, 319.61 and 121.80 is: 182.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.38 : 319.61 = 121.80 : x
  2. Step 2: Convert to fraction form
    213.38/319.61 = 121.80/x
  3. Step 3: Cross multiply
    213.38x = 319.61 × 121.80
  4. Step 4: Simplify right side
    213.38x = 38,927.89
  5. Step 5: Solve for x
    x = 38,927.89/213.38
  6. Step 6: Final answer
    x = 182.44

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.