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Finding the Fourth Proportional to 87.23, 120.35 and 69.78

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Solution

The fourth proportional to 87.23, 120.35 and 69.78 is: 96.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.23 : 120.35 = 69.78 : x
  2. Step 2: Convert to fraction form
    87.23/120.35 = 69.78/x
  3. Step 3: Cross multiply
    87.23x = 120.35 × 69.78
  4. Step 4: Simplify right side
    87.23x = 8,397.67
  5. Step 5: Solve for x
    x = 8,397.67/87.23
  6. Step 6: Final answer
    x = 96.28

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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.