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Finding the Fourth Proportional to 156.21, 213.72 and 155.61

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Solution

The fourth proportional to 156.21, 213.72 and 155.61 is: 212.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.21 : 213.72 = 155.61 : x
  2. Step 2: Convert to fraction form
    156.21/213.72 = 155.61/x
  3. Step 3: Cross multiply
    156.21x = 213.72 × 155.61
  4. Step 4: Simplify right side
    156.21x = 33,256.97
  5. Step 5: Solve for x
    x = 33,256.97/156.21
  6. Step 6: Final answer
    x = 212.90

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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.