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Finding the Fourth Proportional to 155.09, 213.72 and 120.05

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Solution

The fourth proportional to 155.09, 213.72 and 120.05 is: 165.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.09 : 213.72 = 120.05 : x
  2. Step 2: Convert to fraction form
    155.09/213.72 = 120.05/x
  3. Step 3: Cross multiply
    155.09x = 213.72 × 120.05
  4. Step 4: Simplify right side
    155.09x = 25,657.09
  5. Step 5: Solve for x
    x = 25,657.09/155.09
  6. Step 6: Final answer
    x = 165.43

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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.