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Finding the Fourth Proportional to 87.32, 131.45 and 78.50

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Solution

The fourth proportional to 87.32, 131.45 and 78.50 is: 118.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.32 : 131.45 = 78.50 : x
  2. Step 2: Convert to fraction form
    87.32/131.45 = 78.50/x
  3. Step 3: Cross multiply
    87.32x = 131.45 × 78.50
  4. Step 4: Simplify right side
    87.32x = 10,318.83
  5. Step 5: Solve for x
    x = 10,318.83/87.32
  6. Step 6: Final answer
    x = 118.17

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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.