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Finding the Fourth Proportional to 161.72, 223.18 and 91.78

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Solution

The fourth proportional to 161.72, 223.18 and 91.78 is: 126.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.72 : 223.18 = 91.78 : x
  2. Step 2: Convert to fraction form
    161.72/223.18 = 91.78/x
  3. Step 3: Cross multiply
    161.72x = 223.18 × 91.78
  4. Step 4: Simplify right side
    161.72x = 20,483.26
  5. Step 5: Solve for x
    x = 20,483.26/161.72
  6. Step 6: Final answer
    x = 126.66

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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.