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Finding the Fourth Proportional to 87.30, 131.43 and 79.86

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Solution

The fourth proportional to 87.30, 131.43 and 79.86 is: 120.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.30 : 131.43 = 79.86 : x
  2. Step 2: Convert to fraction form
    87.30/131.43 = 79.86/x
  3. Step 3: Cross multiply
    87.30x = 131.43 × 79.86
  4. Step 4: Simplify right side
    87.30x = 10,496.00
  5. Step 5: Solve for x
    x = 10,496.00/87.30
  6. Step 6: Final answer
    x = 120.23

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.