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Finding the Fourth Proportional to 213.39, 319.86 and 103.55

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Solution

The fourth proportional to 213.39, 319.86 and 103.55 is: 155.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.39 : 319.86 = 103.55 : x
  2. Step 2: Convert to fraction form
    213.39/319.86 = 103.55/x
  3. Step 3: Cross multiply
    213.39x = 319.86 × 103.55
  4. Step 4: Simplify right side
    213.39x = 33,119.90
  5. Step 5: Solve for x
    x = 33,119.90/213.39
  6. Step 6: Final answer
    x = 155.21

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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.