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Finding the Fourth Proportional to 161.31, 222.50 and 128.64

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Solution

The fourth proportional to 161.31, 222.50 and 128.64 is: 177.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.31 : 222.50 = 128.64 : x
  2. Step 2: Convert to fraction form
    161.31/222.50 = 128.64/x
  3. Step 3: Cross multiply
    161.31x = 222.50 × 128.64
  4. Step 4: Simplify right side
    161.31x = 28,621.76
  5. Step 5: Solve for x
    x = 28,621.76/161.31
  6. Step 6: Final answer
    x = 177.43

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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.