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Finding the Fourth Proportional to 87.45, 120.69 and 65.58

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Solution

The fourth proportional to 87.45, 120.69 and 65.58 is: 90.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.45 : 120.69 = 65.58 : x
  2. Step 2: Convert to fraction form
    87.45/120.69 = 65.58/x
  3. Step 3: Cross multiply
    87.45x = 120.69 × 65.58
  4. Step 4: Simplify right side
    87.45x = 7,914.85
  5. Step 5: Solve for x
    x = 7,914.85/87.45
  6. Step 6: Final answer
    x = 90.51

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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.