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Finding the Fourth Proportional to 87.31, 119.95 and 78.22

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Solution

The fourth proportional to 87.31, 119.95 and 78.22 is: 107.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.31 : 119.95 = 78.22 : x
  2. Step 2: Convert to fraction form
    87.31/119.95 = 78.22/x
  3. Step 3: Cross multiply
    87.31x = 119.95 × 78.22
  4. Step 4: Simplify right side
    87.31x = 9,382.49
  5. Step 5: Solve for x
    x = 9,382.49/87.31
  6. Step 6: Final answer
    x = 107.46

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.