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Finding the Fourth Proportional to 155.25, 213.71 and 138.87

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Solution

The fourth proportional to 155.25, 213.71 and 138.87 is: 191.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.25 : 213.71 = 138.87 : x
  2. Step 2: Convert to fraction form
    155.25/213.71 = 138.87/x
  3. Step 3: Cross multiply
    155.25x = 213.71 × 138.87
  4. Step 4: Simplify right side
    155.25x = 29,677.21
  5. Step 5: Solve for x
    x = 29,677.21/155.25
  6. Step 6: Final answer
    x = 191.16

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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.