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Finding the Fourth Proportional to 155.17, 213.10 and 138.75

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Solution

The fourth proportional to 155.17, 213.10 and 138.75 is: 190.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.17 : 213.10 = 138.75 : x
  2. Step 2: Convert to fraction form
    155.17/213.10 = 138.75/x
  3. Step 3: Cross multiply
    155.17x = 213.10 × 138.75
  4. Step 4: Simplify right side
    155.17x = 29,567.63
  5. Step 5: Solve for x
    x = 29,567.63/155.17
  6. Step 6: Final answer
    x = 190.55

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.