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Finding the Fourth Proportional to 213.45, 319.89 and 103.81

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Solution

The fourth proportional to 213.45, 319.89 and 103.81 is: 155.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.45 : 319.89 = 103.81 : x
  2. Step 2: Convert to fraction form
    213.45/319.89 = 103.81/x
  3. Step 3: Cross multiply
    213.45x = 319.89 × 103.81
  4. Step 4: Simplify right side
    213.45x = 33,207.78
  5. Step 5: Solve for x
    x = 33,207.78/213.45
  6. Step 6: Final answer
    x = 155.58

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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.