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Finding the Fourth Proportional to 87.28, 120.40 and 59.65

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Solution

The fourth proportional to 87.28, 120.40 and 59.65 is: 82.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.28 : 120.40 = 59.65 : x
  2. Step 2: Convert to fraction form
    87.28/120.40 = 59.65/x
  3. Step 3: Cross multiply
    87.28x = 120.40 × 59.65
  4. Step 4: Simplify right side
    87.28x = 7,181.11
  5. Step 5: Solve for x
    x = 7,181.11/87.28
  6. Step 6: Final answer
    x = 82.28

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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.