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Finding the Fourth Proportional to 87.74, 131.34 and 74.78

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Solution

The fourth proportional to 87.74, 131.34 and 74.78 is: 111.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.74 : 131.34 = 74.78 : x
  2. Step 2: Convert to fraction form
    87.74/131.34 = 74.78/x
  3. Step 3: Cross multiply
    87.74x = 131.34 × 74.78
  4. Step 4: Simplify right side
    87.74x = 9,821.61
  5. Step 5: Solve for x
    x = 9,821.61/87.74
  6. Step 6: Final answer
    x = 111.94

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.