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Finding the Fourth Proportional to 87.91, 131.79 and 53.20

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Solution

The fourth proportional to 87.91, 131.79 and 53.20 is: 79.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.91 : 131.79 = 53.20 : x
  2. Step 2: Convert to fraction form
    87.91/131.79 = 53.20/x
  3. Step 3: Cross multiply
    87.91x = 131.79 × 53.20
  4. Step 4: Simplify right side
    87.91x = 7,011.23
  5. Step 5: Solve for x
    x = 7,011.23/87.91
  6. Step 6: Final answer
    x = 79.75

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.