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Finding the Fourth Proportional to 87.33, 120.21 and 66.57

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Solution

The fourth proportional to 87.33, 120.21 and 66.57 is: 91.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.33 : 120.21 = 66.57 : x
  2. Step 2: Convert to fraction form
    87.33/120.21 = 66.57/x
  3. Step 3: Cross multiply
    87.33x = 120.21 × 66.57
  4. Step 4: Simplify right side
    87.33x = 8,002.38
  5. Step 5: Solve for x
    x = 8,002.38/87.33
  6. Step 6: Final answer
    x = 91.63

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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.